The Didache, or Teaching of the Twelve Apostles, written in A.D. 80, begins with a frank assessment of the culture and the Christian Faith. “There are two ways, one of life and one of death: and great is the difference between the two ways.” The text then discusses the way of life which combines the Ten Commandments and the teachings of Christ. An important part of the way of life is morality, and the particulars of moral living involve marriage and the conjugal act:
“You shall not commit adultery.
You shall not seduce boys.
You shall not commit fornication.
You shall not steal.
You shall not practice magic.
You shall not use potions.
You shall not procure abortion, nor destroy a newborn child.”
The Didache urged Christians to avoid these practices and choose the way of life in imitation of Christ the Lord.
(Steve Weidenkopf, Of Human Life course material, Ch. 1)