On May 21, 2016, Pastor Blackwell was installed as the Senior Pastor of the Southwest Philadelphia Seventh-day Adventist Church (SWP). Prior to this assignment He pastored the following churches: Hadley Community SDA Church in Southeast Washington, D. C.; the Columbia Community Center of SDA Church in Columbia, MD; the Unity SDA Church in Frederick, MD; Millsboro SDA Church in Millsboro, DE; the First SDA Church in Coatsville, PA and the Rehoboth SDA Church in Reading, PA.
In addition to pastoring churches, Pastor Blackwell has been blessed to serve as Chaplain for the Pennsylvania State Police. In 2012 he was selected to serve as Senior Chaplain which is the top position of the chaplains. He holds the rank of Major and serves as a Chaplain for the Maryland Defense Force, a paramilitary group which works with the Army National Guard.