St. Paul in First Corinthians 7 extols the spiritual value of celibacy: “It is good for a man not to marry. ... I wish that all men were as I am.” Paul explains why: it is so one can serve the Lord single-mindedly. Jesus speaks of men who “become eunuchs for the sake of the Kingdom of Heaven.” In the Book of Revelation 14:4, it says, “These are they which were not defiled with women; for they are virgins. These are they which follow the Lamb whithersoever he goeth.”
Jesus was celibate, as were John the Baptist and (according to Christian tradition) Mary. There is ample evidence that celibacy was highly esteemed in the early Church, and that in the first centuries those in ordained ministry were expected either to be unmarried, or if already married to give up sexual relations with their wives. By the year 400 or so, this was a Church law throughout most of the Western Church. In the Eastern Church, the rule of celibacy was weaker: bishops had to be celibate, but the lower orders of clergy could be married -— but if single when ordained they had to remain single.
This is a Roman Catholic tradition, not Protestant!