The phrase "what God has joined together" is a reference to marriage and divorce, and it comes from Jesus teaching on marriage and divorce found in Mark 10:1–12 and Matthew 19:1–12. Jesus point is that a married couple is something that "God has joined together," and once a couple is married, they have been joined together by God Himself, and the union is meant to be for life. This principle holds true despite the faith (or lack thereof) of the couple. Therefore, the phrase "what God has joined together" means that once a couple is married, they have been joined together by God, and the union is meant to be for life, and no human being has the right to break that union.