The betrayed marriage partner sometimes is angry or in great pain, so trusting in God is very important, as is a lot of talking and working at forgiveness and healing. The story of Hosea and Gomer the unfaithful is told, and another story also ending well. A serious commitment to marriage with some real-life examples, is told.
So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.