When did Christians begin to practice monogamy?

Answer 1

Genesis 2:24 implies that monogamy was God's intention from the beginning. When he created man in his own image he later took woman out of man.

The fullness of the image of God is both masculine and feminine. The Bible often uses feminine terms for God and yet he is addressed as Father.

When Gen.2:24 says that when a man is married he becomes one flesh with his wife it implies a return to the state prior to separation. When a man and a woman marry they represent the fullness of God. Monogamy was God's original intention but it was ignored by many. Solomon was the wisest man who ever lived but the Bible says that he was turned away from God by his many wives. Jesus used this verse in Genesis to teach monogamy and so from the beginning Christianity has been monogamous. Christians were converted from paganism where polygamy was rife. Therefore the qualifications for an elder and a deacon are that they be the husband of one wife. See 1 Timothy 3:2.