The World Mission Society Church of God is a new religious movement established by Ahn Sahng-hong in South Korea in 1964. The church believes that Ahn Sahng-hong is the Second Coming of Jesus, and that Zahng Gil-jah is God. Its headquarters as well as its main church are located Sungnam City, Kyunggi Province, near Seoul.

Ahn Sahng-hong founded the Church of God in South Korea on 28 April 1964. During his lifetime, there were 13 branches, and the headquarters were located in Busan. After Ahn Sahng-hong died on 25 February 1985, a general assembly of all the church leaders was held in Busan on 4 March 1985. In this meeting, they recognized Kim Joo-cheol as Ahn Sahng-hong's successor and Zahng Gil-jah as Ahn Sahng-hong's spiritual bride. The headquarters were moved from Busan to Seoul on 22 March. However, in April, leaders of 2 out of 13 churches opposed the doctrine of the spiritual bride and split. They formed the minority group NCPCOG. The majority group of 11 churches, led by Kim Joo-cheol, held a meeting in Seoul on 2 June 1985. During this meeting, they affirmed two major doctrines: that Ahn Sahng-hong should be regarded as the Second Coming of Christ and Zahng Gil-jah should be regarded as God the Mother. They also changed the church's name to Witnesses of Ahn Sahng-hong Church of God. Around 1997, the Witnesses of Ahn Sahng-hong Church of God established a non-profit organization titled the World Mission Society Church of God for the purpose of registering and managing the organization's assets.

The church regards Ahn Sahng-hong as the Second Coming of Jesus Christ, calling him "Christ Ahn Sahng-hong." According to a trinitarian view of hypostasis, Ahn is consequently also the Holy Spirit, God the Father, and thus God. They conduct prayers in the name of Ahn Sahng-hong instead of the name of Jesus Christ. They argue that just as christians prayed in the name of Jesus after He came as the Christ, they now pray in the name of the Second Coming Christ.

The church believes Zahng Gil-jah, an elderly lady from South Korea, to be God the Mother, a female image of God titled Heavenly Mother or simply Mother, and believes that together with Ahn Sahng-hong she should be seen as God (for which the church commonly uses the Hebrew plural word: Elohim).

This church teaches that keeping the Lord's Supper on the Passover is a biblically supported Christian tradition. They celebrate the resurrection on the Sunday following Passover. The church cites Polycrates and Polycarp, known as Quartodecimans, as the basis for keeping the Lord's Supper on the Passover. The Quartodecimans were likely considered 'orthodox' among Christians in Palestine and Asia Minor during early church history. However, After the Paschal Controversy and the First Council of Nicaea, they were classified as heretical.

The church states that according to its interpretation of Exodus 20:4, items such as crosses and statues are considered a form of idolatry and are not erected on or in their churches.

Witnesses of Ahn Sahng-hong Church of God announced that "1988 is the end of the world" citing Matthew 24:32–34, as Ahn had done in his 1980 book The Mystery of God and the Spring of the Water of Life. A few thousand members of Witnesses of Ahn Sahng-hong Church of God gathered on a mountain in Sojeong-myeon, Yeongi County, South Chungcheong Province awaiting the coming of Christ Ahn Sahng-hong, preparing for the rapture and the salvation of 144,000 souls. When Ahn failed to appear and nothing happened the church updated their apocalyptic forecast and scheduled it for the opening of the 1988 Olympics in Seoul later that year where the members gathered and preached the end of the world would come by the end of 1988 and that Ahn Sahng Hong would come again. The WMSCOG later claimed it was a fulfillment of the preaching of Jonah.

At least two former members in South Korea accused Zahng Gil-jah and Kim Joo-cheol who declared 1988, 1999 and 2012 as the end of the world in order to defraud members for more wealth.

This church primarily evangelizes the doctrine of 'God the Mother' in shopping malls, campuses, parks, door-to-door visits and on the streets. A church member mentioned that they typically engage in evangelism in open, visibly safe areas. Some ex-members and cult researchers have criticized the group's recruiting efforts as very aggressive, claiming that the church targets psychologically vulnerable people, particularly those going through a major life transition or with a void in their lives, as well as those with greater access to money, young white people who appear wealthy, college students and returning veterans. There are also claims that the church targets women and ethnic minorities.

After investigating the church's evangelism activities, Oxford Police said that nothing incriminating has been reported. They announced via social media that the World Mission Society Church of God is a legitimate church expanding to the area, and that sharing information door to door is allowed according to the Freedom of Relligion Act. Newport News Police commented, "As far as we can tell, it’s just a group that just wants citizens to attend their church." Fresno Police stated they could not find any reports of criminal behavior associated with them.

Since 2018, there have been rumors spread through social media that the evangelism about 'God the Mother' of the WMSCOG is linked to human trafficking. Local police investigations have confirmed that these rumors are false. A supervisor in the Vice-Criminal Intelligence Unit of the Fresno Police stated that there is no evidence of human trafficking activity and that research using government and non-government sources didn’t show any criminal activity associated with the individuals or the church elsewhere. The rumor is estimated to have started on social media in early 2018 and spread to various regions, particularly through campus student associations. Investigations into the rumor were conducted at the University of Mississippi, the University of Louisville, Vanderbilt University, the University of Georgia, the University of South Carolina, the University of Utah, Oberlin College, Texas State University, among others.

The church stated that due to false rumors, the church and its members experienced religious discrimination and harm. They reported that members had been threatened, faced murder threats, pepper spray attacks, and harassing phone calls. There was even an incident where someone almost ran over members with a vehicle. In response to the church's reports of these incidents, the police stationed patrol cars at the church. The church issued a statement requesting an end to the false rumors and unfair harassment against its members.

Many students, across multiple campuses, reported evangelism concerning the 'God the Mother' doctrine. There were concerns that they primarily target young women and approach men for human trafficking purposes due to false rumors circulating on social media. They approach students to ask if they believe in God the Mother, and often invite them to study groups or Bible study session. In New Zealand, their activities have been reported at the University of Otago, the University of Waikato, and the University of Auckland.

Rowan University’s spokesperson stated that they follow the same rules as other visiting groups and have done nothing wrong. Fresno City College’s spokesperson said that they are not doing anything wrong and no malicious activity has ever been reported Wichita State University police stated that while the member of the church approach people to talk about the Bible, they were not aggressive. People were making their own decisions to go with them, and there was no evidence of kidnapping or illegal activities. A Deputy of the University of South Carolina Police Department said that they're very cognizant of the First Amendment and people's freedom of religion and they don't want to curtail that haven't heard of anything criminal.

Some college campuses in the U.S. banned the church's recruiters for trespassing or proselytizing without permission. The University of Memphis and Ole Miss barred the church's evangelism activities from their campuses. A church member at the University of Memphis mentioned that there had been no issues about spreading messages for years and believed the actions were a result of false allegations on social media. Rochester University stated that, because the church is not affiliated with the Interfaith Chapel, its members are not authorized to be on campus. Students should not feel in danger from this group but are advised to exercise caution. The Otago University Students' Association in Dunedin disaffiliated from the Elohim World Academy following complaints from students about deceptive and coercive recruitment methods. The University of Otago's Proctor had considered trespassing members of the group but ruled it out since that would have violated the New Zealand Bill of Rights Act 1990's provisions on religious freedom and freedom of expression.

The World Mission Society Church of God has a university volunteer division called the ASEZ ("Save the World from A to Z"). The organization, which recruits on university campuses, claims that students can be members of ASEZ without being members of the church, but this has been contested. According to the Yale Daily News, Yale students who were approached and attended meetings of the group stated that the organization was not framed as being separate from the church, and that representatives mainly focused on religious aspects rather than volunteerism. One student was told that the group's slogan was for "saving the people on earth from the end of the world." According to Steven Hassan, an author and counselor specializing in cults, many destructive cults use small "fringe groups" to deceptively recruit members, of which the ASEZ is an example.

Some former members and cult researchers have criticized the group, describing it as a cult that exercises excessive control over its members, enforces separation from family and friends, exploits its members excessively, violates laws, and avoids transparency and accountability. In a civil suit filed by a former member against the church, the courts stated that although a church can be held liable for tortious conduct and contractual obligations, neither was applicable in this case.

Michele Colon, a former member who attended WMSCOG in New Jersey for two years, claimed in her 2013 civil lawsuit against the church that the group is a profit-driven cult that uses psychological control tactics to prevent members from exposing its criminal and illegal behavior. In December 2015, In an interview with People magazine, Colon, whose claims were generally contradicted by the church but generally supported in interviews with six other former WMSCOG members, described WMSCOG as a "doomsday cult" and "opportunistic." She claimed that the group recruits people undergoing life transitions or feeling a void, exploiting this vulnerability to draw them in. She said that the church manipulates members with "fear and guilt" and constant repetition, and that it "micromanaged" her life, including controlling her music choices and forbidding internet use. She claimed that church leaders do not disclose until members are fully committed that their "God the Mother" is actually a living South Korean woman in her 70s, known by multiple names and various spiritual titles, who is reportedly the spiritual wife of the deceased founder, Ahn Sahng-hong. At least one former member has sued them for urging her to have an abortion, and others have accused the church of discouraging pregnancy in anticipation of the world ending in 2012.

Colon's lawsuit seeking damages for the tortious conduct of the church was almost entirely rejected by the district and appellate state courts. The district courts dismissed her claims, citing the "religious freedom" element of the First Amendment to the U.S. Constitution. The appellate courts ruled that:

Each claim springs from Colón's contention that WMSCOG is a cult, not a church, and that she was essentially defrauded by this cult. The conflict arises from her disagreement about the manner in which the church implemented its doctrinal beliefs, managed its clergy and parishioners, and invested donations. Therefore, Colón's complaint necessarily required the court to examine the interior workings and structure of the church, a constitutionally unacceptable process. Although a church may clearly be held liable for tortious conduct and obligated on contractual undertakings, neither existed in this case.

An exclusive article reported claims from a former member in New Zealand. She alleged that members were expected to follow strict rules, such as separating from social media and non-church friends, attending masses and recruitment sessions, tithing ten percent of their income, avoiding jeans, rejecting music and masturbation, and losing weight to meet Korean beauty standards. She also claimed that members, including minors, were shamed for failing to meet the church’s standards and were ranked based on their recruitment rates. Additionally, she stated that church members were shown graphic videos of Hell and that pastors arranged marriages between congregants. The article's writer mentioned that the police initiated an investigation into the group. However, when a request was made to the New Zealand Police in 2023 for information regarding both the Elohim Academy and the church, the Police responded that no investigation had been conducted into either entity.

Rick Alan Ross, cult researcher and deprogrammer describes the WMSCOG as "a very intense group ... similar to the Unification Church [of] Sun Myung Moon—the Moonies", comparing WMSCOG indoctrination methods to those of the Unification Church. He claims that the WMSCOG has driven members into bankruptcies due to excessive donations, and claims that some have lost their jobs to excessive demands by the group and associated sleep deprivation. Ross says that members often are sent to group housing and shared apartments, becoming isolated and alienated from family and friends, even spouses and adult children. Ross notes the group, which recruits members on university campuses, at malls and other shopping sites, has no meaningful accountability for leadership—a "dictatorship in Korea"—nor for the millions in revenue it receives.

Steven Hassan, an author and mental health counselor who specializes in cults, described the experiences of Yale students exposed to the group as matching those of what he calls "authoritarian" or "destructive" cults.

The World Mission Society Church of God is one of many controversial and globalized grassroots Christian new religious movements that emerged in South Korea and has experienced rapid growth over the past 20 years since the 2000s.

The Korean Christian community, including the National Council of Churches in Korea and the Christian Council of Korea, has "harshly criticized" the deification of Ahn Sahng-hong and Zahng Gil-jah. They have officially condemned the church as a blasphemous and heretical cult, opposed by various denominations.

A heresy expert of the Christian Council of Korea was found guilty by the courts of attempting to forcibly convert members of the World Mission Society Church of God, thereby violating their human rights and religious freedom. Pastor Jin, vice chairman of the Christian Council of Korea's Countermeasure Committee against Heresy and an editor at 'Modern Religion', confined members of the church in attics or prayer rooms and conducted forced conversion sessions. Members who did not convert were forcibly admitted to psychiatric hospitals. The victims filed lawsuits against Pastor Jin and others involved in the confinement. In 2008, the court sentenced Pastor Jin to a suspended prison term for night-time group coercion and aiding confinement, acknowledging the serious violation of personal freedom and religious freedom under the guise of conversion persuasion. The accomplices and psychiatrists involved were also found guilty. Shin Hye-sook, director of the Women's Cultural Center, criticized the actions, stating that using violence against people of different religions indicates a lack of basic religious qualities. Religious groups also criticized the intolerance and judgment of different denominations as reminiscent of the medieval religious dark ages.

In the past, the World Mission Society Church of God rented parts of collective buildings, but after 2007, church construction increased. As the number of buildings of the Church increased, Korean Christian organizations held protests and filed complaints to interfere with the church's construction. They stated, "The reason we must oppose the construction of this church on its own land with its own money is that this church is a cult." Most local governments approved the church's construction, and approximately 150 church buildings were constructed over the 10 years following 2007. However, a few local governments, including Yeosu City and Ulsan City, rejected the construction approvals, citing complaints and traffic congestion. The World Mission Society Church of God filed administrative lawsuits. The Korean courts ruled that "the collective petitions from religious organizations and nearby residents are merely personal and subjective evaluations of this church and cannot be seen as objective evidence that this religion causes harm. It is difficult to view this church as an anti-social religious group or to see its activities as anti-social. The church meets the legal parking requirements and there are no legal violations." Consequently, the courts declared the local governments' refusals to approve the church's construction to be illegal.

In 2016, the Wonju city government denied the construction approval for the Church of God in Wonju City, citing complaints and concerns regarding traffic congestion. However, there was controversy over the unfairness of the Wonju city government's refusal. The building applied for had about twice the number of legally required parking spaces, but the Wonju city government demanded parking spaces for 1,000 cars, assuming 1,000 church members. This calculation included children as drivers. Major South Korean media outlets reported suspicions of religious bias by the mayor of Wonju City regarding the rejection. Church members protested against the Wonju city government's administrative action by phone. There were more than 30,000 complaint calls made between May 30 and June 1, 2016. These complaints disrupted the city hall's complaint processing work. The church filed an administrative appeal against the Wonju city government's action, but the Administrative Appeals Commission dismissed it. The World Mission Society Church of God considered filing an administrative lawsuit against the Wonju city government.

Subsequently, in administrative lawsuits between the World Mission Society Church of God and other local governments, such as Yeosu City Hall and Ulsan City Hall, which had rejected construction approvals, the courts ruled that the local governments' refusals to approve the church's construction were illegal Although there was no administrative lawsuit against the Wonju city government, it changed its stance and in 2019 approved the use of the building for church purposes. They approved the previously rejected church construction, and the church held a dedication ceremony for the newly constructed church in 2023. When the World Mission Society Church of God applied to build an additional church in Taejang-dong, Wonju City, there were complaints filed again. However, the Wonju city government approved the construction application, stating there were no legal issues.

In 2018, the Vietnamese Committee for Religious Affairs warned against the World Mission Society Church of God, describing it as cult-like. The government accused the group of deceptive recruitment, manipulative indoctrination, doomsday predictions, urging cash donations, and encouraging members to abandon their families. Authorities seized the Church’s assets in Hanoi, Saigon, and other provinces, interrogated hundreds of members, and accused Church leaders of brainwashing and micromanaging members' lives.

Asia News reported that many consider these allegations to be false, used by Vietnamese security forces to discredit certain groups. Fr. Le Ngoc Thanh, a Redemptorist priest in Saigon, said he was afraid that the propaganda campaign against the World Mission Society Church of God was designed to create tensions between religious and non-religious people. Vietnam's independent media outlet, IJAVN reported that "the Ministry of Home Affairs recently requested local authorities to disband and revoke licenses for religious groups associated with the 'Church of God' and 'Heavenly Mother' focus, preventing these organizations from regrouping and forming new centers of activity. This is difficult to understand because, even without any discovered violations of the law, licenses are still being revoked".

The governments of several countries, including Singapore, have labeled the organization as a "cult", or "cult-like".

The church often purchases buildings from other churches. If the acquired building has stained glass windows, they sometimes preserve or remove them. When the WMSCOG in Washington, D.C., acquired a church building in Capitol Hill, they renovated it while preserving most of its historic elements. However, they attempted to replace the stained glass windows with clear glass. This raised concerns among residents, who contacted the Historic Preservation Office (HPO). The church filed an application with the HPO to replace the stained glass windows, citing their religious belief that prohibits worship in the presence of images, as well as concerns about lead safety and energy efficiency. The D.C. government ruled that the church had created a conflict between preservation laws and its religious freedom by failing to conduct due diligence before purchasing the building. They ordered the restoration of the stained glass windows. After the restoration, the church applied for a permit to install storm window over the stained glass and the HPO found that regulations did not prohibit the installation of storm windows and that a permit was not required. The church then installed storm windows.

The Mystery of God and the Spring of the Water of Life (1980) has 38 chapters in total. The WMSCOG removed three chapters from "The Mystery of God and the Spring of the Water of Life", namely Chapter 1: Restoration of Jerusalem and the Prophecy of 40 Years, Chapter 11: Let Us Reveal the Truth from the History Books About the Church, and Chapter 36: Elijah Will Be Sent.

The "New Covenant Passover Church of God" (NCPCOG) which is the group that has split with the WMSCOG, claimed that the WMSCOG had changed the first edition dates of "The Mystery of God and the Spring of the Water of Life", "The Last Plagues and the Seal of God" and "Visitors from the Angelic World" to 1967 once upon a time. The NCPCOG also refuted the claim by the WMSCOG that Ahn Sahng-hong had the book "The Law of Moses and the Law of Christ", and said that Ahn Sahng-hong has never published this book, but it seems to have been compiled with reference to Ahn Sahng-hong's book "The New Testament and the Old Testament".

A media outlet owned by the Church of God reports to have more than 7,500 churches, and 3.3 million registered members in the world's 175 countries. However, an external account mentions that the number of church members is estimated to have only been around 100,000 in 2013, contrary to Kim Joo-cheol's claims.

UK ZION, a World Mission Society Church of God chapter, was awarded The Queen's Award for Voluntary Service in 2016.

• World Mission Society Church of God Official website (English)
• World Mission Society Church of God Official website (Korean)
• WATV Media Cast Media website (English)
• World Mission Society Church of God in the U.S. USA based website (English)
• World Mission Society Church of God in Singapore Singapore based website (English)
• World Mission Society Church of God in Philippines Philippines based website (English)
• "NBC Investigates – World Mission Church of God...," December 4, 2016, The Today Show, host Ronan Farrow – NBC News on YouTube