William has a B.B.A. in Business Management with a minor in Marketing from Abilene Christian University and an A.A. in Business Administration from Central Christian College in Kansas. His wife the Rev. Dr. Roberta Mosier-Peterson received her DMin from Northeastern Seminary.

William and Roberta have been married over 25 years and have no biological children but like to say they have parented hundreds of children during their career in ministry including pastoral ministry and service at Oakdale Christian Academy in Jackson, Kentucky where William served as director of development for 10 years. 

William serves on the strategic leadership team at Northeastern and is responsible for all fundraising efforts including the annual fund, scholarships, and estate planning.