Question: "How should a Christian spouse handle an adulterous affair that has resulted in a child?"
Answer: Marriage is a covenant that brings a couple together both spiritually and physically. Infidelity causes a devastating blow that tears through the oneness of marriage, often resulting in irreparable damage. This can be especially true if a child is conceived through adultery.
A parent's responsibility to his child is not determined by the circumstances of the child's conception. Bringing a child into the world through an adulterous act is unfavorable for all parties involved, but it is important to remember that the child is innocent and deserves to have two parents in his/her life.
If a wife decides to remain with her husband even after he has had an affair resulting in a child, she must also be prepared to forgive the sin. The Bible tells us that Christians are to forgive each other, just as God has forgiven us (Matthew 6:14-15). This means making the choice to put behind her the feelings of anger and jealousy.
Ideally, a wife whose husband has fathered a child with someone else will be able to embrace the child as a stepson or stepdaughter. She should not stand in the way of her husband forming a relationship with his child, even though this might be painful for her. He has financial, spiritual, and emotional obligations to all his children (Ephesians 6:4).
Although adultery is a sin with the potential to break up families, it need not be the end of a marriage. Instead, the couple should work even harder at rebuilding their relationship on the firm foundation of faith and obedience in Jesus Christ. Only the grace and mercy of God and the strong faith in Christ will get a couple through this difficult situation. But grace, mercy, and faith are all the gifts of God through the Holy Spirit and they are available from God to those who truly seek to glorify Him through all the difficulties of life.