Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 9. Ascetic Tendencies.” Sections 104-108, Loc. 17159-17485.
§ 108. Celibacy of the Clergy.
Schaff opens this section of his text with a fairly comprehensive bibliography of the topic (Schaff 2014, Loc. 17367). The essence of clergy, as representative of Christ, always included “sexual temperance” (Schaff 2014, Loc. 17391). The fact that Jesus never married suggested priestly celibacy. Schaff notes that various pagan religious groups also practiced celibacy. However, it was never a matter of law among Christians prior to Nicea (Schaff 2014, Loc. 17397). Schaff further notes that the apostle Paul “classes the prohibition of marriage. . . among the doctrines of demons” (Schaff 2014, Loc. 17402). Marriage had always been seen as honorable.
However, especially in the West, an approval of priestly celibacy tended to grow up over time (Schaff 2014, Loc. 17413). Schaff makes it clear that priestly marriage was common in early Christianity at least into the fifth century (Schaff 2014, Loc. 17428). At the same time, it was nt unusual for clerics to choose not to marry. Many who did had unhappy marriages.
For a reason which Schaff does not specify, the custom of not allowing clergy to remarry grew after the third century (Schaff 2014, Loc. 17434). The practices, in both East and West, continued to become more rigorous over time (Schaff 2014, Loc. 17440). As time passed, clergy who were ordained were prevented from marrying. Those who were already married were prohibited from “conjugal intercourse,” effectlvely breaking their marriages (Schaff 2014, Loc. 17445).
After the Council of Nicea, Schaff finds the Western Church tending to become more limiting of marriage and the Eastern Church less limiting (Schaff 2014, Loc. 17461). In the West, complete celibacy of clergy became the rule by the late 5th century (Schaff 2014, Loc. 17471).
Schaff emphasizes that his objection is not to celibacy or marriage, but to the unnatural and extrabiblical practice of requiring either position (Schaff 2014, Loc. 17477).