The Bible presents monogamy as the plan that conforms most closely to God’s ideal for marriage. The Bible says that God’s original intention was for one man to be married to only one woman: “For this reason, a man will leave his father and mother and be united to his wife [not wives], and they will become one flesh [not fleshes]”. In the New Testament, Timothy and Titus give “the husband of one wife” in a list of qualifications for spiritual leadership. The phrase could literally be translated as “a one-woman man.” Ephesians speaks of the relationship between husbands and wives. When referring to a husband (singular), it always also refers to a wife (singular). “For the husband is the head of the wife [singular] … He who loves his wife [singular] loves himself.
Genesis 2:24; Ephesians 5:22-33; 1 Timothy 3:2,12; Titus 1:6; 1 Corinthians 7:2