Joseph W. Tkach (/təˈkɒtʃ/; March 16, 1927 – September 23, 1995) was the appointed successor of Herbert W. Armstrong, founder of the Worldwide Church of God. Tkach became President and Pastor General of the church upon the death of Armstrong in 1986. Tkach spearheaded a major doctrinal transformation of the Worldwide Church of God, abandoning Armstrong's unconventional doctrines and bringing the church into accord with orthodox evangelical Christianity. His son, Joseph Tkach Jr., continued his work and in 1997 the Worldwide Church of God became a member of the National Association of Evangelicals.