How did celibacy become mandatory for priests?

Kim Haines-Eitzen, professor of Near Eastern studies, recently wrote a piece on The Conversation website that discusses the origins of Christian celibacy. 

"By the third and fourth centuries A.D., Christian writers had begun elevating the practice of celibacy and asceticism," she writes. "They did so by pointing to both Jesus and Paul as models of the ascetic life as well as by carefully interpreting scripture in support of the practice of celibacy."

Read the full article on The Conversation website; it also ran in Newsweek.