William James McDuffie was born and raised in Huntington Station (Long Island), New York. He is the fifth child of seven of the late Reverend James S. McDuffie and the late Mother Edna M. McDuffie. Called to ministry at a young age, he was licensed in 1985, and subsequently ordained as a minister of the Gospel in the Church of God in Christ in 1988. In 2001, under a mandate from the Lord, he established William McDuffie Ministries (WMM), Inc. which consists of several anointed ministries to include Seed of Abraham Christian Center International (SACCI) of Sierra Vista, Arizona. WMM and SACCI are nondenominational, multicultural, full-Gospel, Word of Faith ministries. The mission of WMM and SACCI is to teach the Body of Christ how to submit to and effectively apply the Word of God (Truth), so that each member will experience success in every aspect of the abundant life.

Pastor McDuffie is married to the bride of his youth, the former Yvette E. Miller of Huntington, New York, who faithfully serves with him in ministry as Co-founder and Assistant Pastor of WMM and SACCI. He and his wife reside in Southern Arizona and are the proud parents of two great children, William J. McDuffie II, a United States Marine, and Brittanie Yvette McDuffie, an Airman in the U.S. Air Force. In addition to his biological children, Pastor McDuffie is mentoring and developing several spiritual sons and daughters. An adamant believer in covenant relationships, he is a spiritual son of the Right Reverend Dr. Richard B. Peoples, Sr., Pastor and Presiding Bishop of Faith Outreach Christian Life Center of Hephzibah, GA.

In December 2006, Pastor McDuffie retired from the United States Army after 24 years of service. He is a military graduate of numerous highly technical and leadership schools to include the United States Army Sergeants Major Course and the United States Army First Sergeants Course. He holds an Associates of Applied Science degree in Electronic Technology from Cochise College of Sierra Vista, AZ and a Bachelor of Science degree in Business Administration from Touro University International of Cypress, CA. Pastor McDuffie is currently pursing an MBA with Touro University.