Lumpkin is considered to be one of the leading scholars in the field of ancient religious texts. He has produced over a dozen books on subjects such as Gnosticism, Midrash writings, and the translation of non-canon texts. According to Lumpkin, many non-biblical works influenced modern theology. He has been referenced in such articles as Wikipedia's "Thomas the Apostle", which cites Lumpkin’s The Tao of Thomas. His book entitled The Lost Book of Enoch: A Comprehensive Transliteration is the top selling book on the subject.

Radio interviews on L.A. Talk Radio’s “Max and Friends”, “Rain Making Time” with Kim Greenhouse, and the U.K. Program of “Connecting the Light” have all hosted Lumpkin. Lost Books of the BIble, Angels and Demons, and other interesting subjects were discussed.

Lumpkin now resides in the state of Alabama, where he continues to teach and write.