Martin was born in Brooklyn, New York to George Washington Martin II (1876–1948) and Maud Ainsworth (1892–1966). His father was a prominent figure in the legal profession who served as an assistant District attorney, before working as a criminal trial lawyer. In 1920 George Martin became a county court judge and presided over cases involving some of the notorious Murder Inc criminals.
Martin's mother, Maud Ainsworth, was born in Chicago to Joseph Ainsworth and Annie Young. She was one of several children born of that marriage, but was put up for adoption. She was adopted by her uncle and aunt James McIntyre (theatrical actor) (1857–1937) a vaudevillian (one partner of the black-face duo, "Thomas Heath and Jim McIntyre"), and Emma Maude Young (1862–1935), a dancer and balladeer (known on stage as "Maude Clifford" and "Maud Clifton").
Martin was raised in the Bedford-Stuyvesant area of Brooklyn, and was the youngest of six children. In his earliest years the family lived on Macdonough Street, and then from 1930 onwards on Bainbridge Street, Brooklyn. In the mid-1940s he attended The Stony Brook School where he obtained his high school diploma.
Dr. Martin held four earned degrees including a Master of Arts Degree in Philosophy from New York University, where he was a student alongside television evangelist D. James Kennedy. Kennedy confirmed the fact that Martin had completed all of the coursework for his doctorate, with the exception of his dissertation. He subsequently obtained a Ph.D. in 1976 from California Coast University, which was accredited by the state of California when the degree was awarded. (see Controversies below)
Martin's career as an apologist began at the age of fifteen after being baptized in Hegemen Chapel at The Stony Brook School (Stony Brook, NY). While in college and graduate school, he often skipped eating during his lunch hours to answer a variety of tough questions about the Bible and the Christian faith while standing on the corner of Wall Street and Broadway, in New York City. Martin has indicated in various book dedications and in audio recorded lectures how he was mentored by Frank Gaebelein (Headmaster, The Stony Brook School), Wilbur Smith (1894–1976) (author of the apologetic text Therefore Stand), and the Presbyterian Bible teacher Donald Grey Barnhouse (1895–1960).
Martin's relationship with Barnhouse as his mentor grew over the years, and he was appointed as a regular columnist to Eternity magazine (1955–60). Barnhouse's support for Martin's research and teaching abilities resulted in the reassessment of Seventh Day Adventist theology, raising the profile of his early ministry in the Evangelical movement. He also worked for a time as a research associate for the National Association of Evangelicals.
Martin was ordained as a minister of the Regular Baptists in 1951, but this was revoked in 1953 owing to his remarriage. However, Martin met with the key pastor involved in this revocation and a restoration agreement was apparently reached, as Martin began marrying couples on television and continuing in public pastoral roles with the full knowledge of the Baptist denomination. His status as a minister has been the subject of much controversy but his daughter, Jill Martin Rische, has made more information available that puts much of the controversy to rest. Walter Martin served as a pastor in various churches in New York and New Jersey in the 1950s and 1960s. He also became a regular teacher of Bible study classes at Barnhouse's Church in New York City. In later years Martin would serve as a preacher and Bible teacher at Melodyland Christian Center and then at Newport Mesa Christian Center in California.
Perhaps the greatest public controversy of his early career arose from his studies of Seventh-day Adventist theology. From its earliest days until the 1950s, the Seventh-day Adventist Church was regarded by Evangelical Christians and mainstream Protestants as either an extreme sect or heretical cult. Martin had initially accepted the prevailing Protestant opinion about the heretical status of the Seventh-day Adventists. He indicated his opposition to Adventist teachings in a brief paragraph in the inaugural edition of his book The Rise of the Cults, published in 1955.
However, he reversed his views after a series of interviews with various leaders of the Seventh-day Adventist Church, and on reading Adventist literature. Martin reported his initial findings to Barnhouse, and between 1955-56 a series of small conferences were held, with Barnhouse and Martin meeting Adventist leaders like T. E. Unruh and LeRoy Froom. Barnhouse and Martin then published some of their findings in a series of articles that appeared in Eternity Magazine between September and November 1956. The standpoint taken by Barnhouse and Martin was that Adventists were largely orthodox on central doctrines, but heterodox on lesser doctrines, and so could be classified as belonging in the Evangelical camp. Martin later expanded his position in his 1960 book-length treatment, The Truth About Seventh-day Adventism. Martin's book carried an explanatory foreword by Barnhouse and a statement from H. W. Lowe who was the chairman of the Biblical Study and Research Group of the General Conference of Seventh-day Adventists. While Lowe did not agree with Martin's criticism of the church's distinctive doctrines he nonetheless commended the book for providing a "fair and accurate statement of Adventist teachings." A committee of Adventist leaders themselves wrote and published a companion book, Seventh-day Adventists Answer Questions on Doctrine, in 1957. While many Adventists welcomed the overtures of Barnhouse and Martin, there were other Adventists who questioned the position taken by church leaders in the volume Questions on Doctrine.
In the late 1950s and early 1960s Evangelical opinions were divided over the Martin-Barnhouse stance on the Adventists. Some, like E. Schuyler English, supported Martin, some such as John Gerstner urged a sober and fair hearing, while others, such as Louis Talbot, J. K. van Baalen, Harold Lindsell and Anthony Hoekema, opposed his view. As the controversy ensued among Evangelicals Martin found it was necessary to restate and defend his position and to reply to his critics. To that end Martin reproduced much of the text of his 1960 book, together with critical replies in an appendix "The Puzzle of Seventh-day Adventism" in his 1965 textbook The Kingdom of the Cults. Martin later updated the appendix in the 1985 edition of Kingdom of the Cults, and since his death the editors of the posthumous editions of 1997 and 2003 have continued to update it.
From 1955 to 1965 Martin enjoyed a relationship with Zondervan publishers where he was appointed as director of cult apologetics publications. During this period Zondervan released several publications about cults under his direction, with at least eight books and four booklets written by Martin. His earliest countercult books included Jehovah of the Watchtower, The Christian Science Myth, The Christian and the Cults and The Maze of Mormonism.
In his first handbook, The Rise of the Cults, he wrote about Jehovah's Witnesses, the Theosophical Society, Mormonism, Christian Science, the Unity School of Christianity, and Father Divine, with an exhortation to the church to treat the cults as an important mission-field. Most of the contents of his earliest books reappeared in his major textbook The Kingdom of the Cults, which was first released in 1965.
Martin's primary approach to assessing cults was to focus on what he saw as doctrinal issues, particularly those concerning the person, nature and work of Jesus Christ. Martin emphasized research and quoted directly from the teachings of the opposing denominations; which he called cults, challenging their claims to Christianity by pointing out what he saw as Biblical errors in their theology. (Jill Martin Rische, eldest daughter of Dr. Walter Martin, www.waltermartin.com).
Martin built a reputation as an authority figure on cults based upon integrity. His role as a columnist in Eternity magazine allowed him the freedom to address other topics such as basic Christian doctrines, the theology of Karl Barth, the problem of alcoholism, and reviewing books. His basic approach in apologetics was that of an evidentialist.
Throughout his writing career Martin had articles published in other periodicals including Christianity Today, United Evangelical Action, The Christian Librarian, Christian Life, Christian Research Newsletter, Logos Journal, Moody Monthly, and Our Hope.
In 1960 Martin established the Christian Research Institute in New Jersey, and then in 1974 relocated it to Southern California. In its earliest years Martin's colleagues who were associated with Christian Research Institute included Walter Bjorck, James Bjornstad, Floyd Hamilton, and Shildes Johnson, many of whom went on to publish countercult books.
Through this para-church organisation Martin built up a reference library of primary source material, and sought to train Christians in the art of apologetics and evangelism. He developed a bureau of speakers, and from the early 1960s conceived of the need for a computerized data base of apologetic information. Martin's prescient advocacy of using computer technology for apologetic purposes led to a major conference, the All-Europe Conference on Computer Technique for Theological Research held in Austria in September 1968. This became the subject of the book Computers, Cultural Change and the Christ, which was written by Martin's friend and colleague John Warwick Montgomery.
In 1978 he established a ministry periodical known as Forward, which was redesigned in 1987 as Christian Research Journal. Martin mentored several figures who have become prominent apologists in the Christian countercult movement including Craig Hawkins, Bob and Gretchen Passantino, Elliot Miller, John Weldon, Kenneth Samples, Ron Rhodes, Rich Poll, Ron Carlson, Paul Carden, and Robert M Bowman Jr. Many of the people who have established ministries in the Christian countercult movement regard Martin as the father of the Christian Counter-cult Movement. One indicator of the high esteem in which he was held is that at least twelve books have been dedicated to him. Scores of ministries on cults and apologetics have also begun as a result of Dr. Martin and his ministry.
Martin was also a radio broadcaster who began this side of his ministry on Barnhouse's program. In the mid-1960s Martin regularly appeared as a guest panelist on The Long John Nebel Show, and then founded his own program known as "The Bible Answer Man." Between the mid-1960s until his death in 1989 Martin debated in public various non-Christians such as atheist author/activist Madalyn Murray O'Hair and Hugh Schonfield, theologians of Liberal Christianity like Thomas J. J. Altizer and Bishop John Shelby Spong, and new religious commentators like Roy Masters. He appeared many times on the John Ankerberg television show debating advocates of Freemasonry, the Bahá'í Faith, and other groups.
In the earliest years of his ministry Martin traveled frequently with Billy Graham and World Vision Founder Bob Pierce, addressing thousands in open air church meetings about the theological problems posed by the cults. Martin always emphasized the importance of analysis and primary source materials in determining the true beliefs of groups like Christian Science, Jehovah's Witnesses, Seventh-day Adventists, Mormonism, Spiritualists, Father Divine, Unity School of Christianity and Herbert W. Armstrong's Worldwide Church of God. In 1958 he spoke throughout East Asia and in Ghana, and in 1961 in Northern and Western Europe.
The popularity of Martin's ministry coincided with the Jesus People movement of the early 1970s and the rise of the countercultural interest in East Asian religions and esoteric pathways. As occult interests surfaced in the counterculture, and also as other religious movements and groups like the Hare Krishna, Unification Church, and Children of God emerged, Martin became a much sought after speaker for curious and fearful Christians.
Martin utilised the new technology of cassette tapes, and disseminated many of his public lectures about apologetics questions and cultic groups to thousands worldwide. Several albums were released on The World of the Cults, The World of the Occult, The New Cults, How To Witness to Jehovah's Witnesses, and How to Witness to Mormons. Other albums tackled general apologetics To Every Man An Answer, and topical problems such as abortion, homosexuality and women's liberation (Martin Speaks Out). He later appeared in a series of six films produced by Vision House called Martin Speaks Out on the Cults.
During the 1980s Martin spoke in churches and para-church conferences in Australia and around the world, Brazil, Kenya and New Zealand. His final book dealt with New Age spirituality.
Martin maintained a part-time role as a lecturer in various liberal arts and bible colleges including The King's College, Melodyland School of Theology in Anaheim, California, and was for many years a board member of Gordon-Conwell Theological Seminary. In 1980 he joined John Warwick Montgomery in promoting apologetics through the Master of Arts program at the Simon Greenleaf School of Law.
In the 1980s, Martin was involved in critical debates over the positive confession success theology (also called Word of Faith) of Christian charismatic teachers such as Kenneth Copeland and Kenneth Hagin. While Martin was critical of these teachers' claims concerning their views of Christ, healing, faith, and prosperity, he believed in the perpetuity of charismatic spiritual gifts in the Church. To that end, Martin presented his positive appraisal of spiritual gifts in several audio lectures (waltermartin.com), and by editing with chapter end-notes, a fresh reprint edition of 19th century evangelist Dwight L. Moody's book Secret Power.
Some opponents have made claims that Martin did not have a valid doctorate. Mr and Mrs Robert Brown of Arizona, two Latter-Day Saints, have stated that California Western University, now known as California Coast University (CCU) was not accredited at the time the degree was awarded. In addition some opponents of Martin claim he purchased his doctorate from CCU, which they claim was a degree mill. It must be noted that Martin completed all the coursework at New York University, which is also an accredited school. Furthermore, California Coast University also offers fully accredited programmes, being accredited by the State of California since 1974. Such approval is currently granted by the California Bureau for Private Postsecondary Education. It, however, received national accreditation only in 2005, from the Distance Education and Training Council (DETC). It obtained this status after a study by the US General Accounting Office (GAO), which sought to provide national accreditation to schools that offered high quality education, which concluded that CCU was never a diploma mill and never committed wrongdoing.