Short Answer
This is what the Bible says:
Mark 10:6-8 – From the beginning of creation, ‘God made them male and female.’ ‘Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.’ So they are no longer two but one flesh.
So it’s clear that God’s design for marriage from the beginning for everyone was one man and one woman. Period.
More Info
Unfortunately, not everyone followed that rule, including some godly men who were very blessed by God (Abraham, Jacob, David, Solomon, etc). But don’t mistake that blessing for sanctioning every part of their lifestyle. God has never condoned (approved of) polygamy. In the New Testament, God repeats this rule for leaders (Elders) in the church:
1 Timothy 3:2 – Now an Elder is to be above reproach, the husband of one wife, temperate, self-controlled, respectable, hospitable, and able to teach.
And Paul uses the marriage relationship as the best illustration of Christ and the church:
Ephesians 5:31-32 – “For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh.” This is a profound mystery—but I am talking about Christ and the church.
This illustration makes no sense in a world where polygamy is ok.
