Sex before marriage has become so commonplace in our society, even to the point of being expected, that many professing Christians don't even consider it to be a sin. Our culture assumes that people do not possess the amount of self-control necessary for abstaining until marriage, so the idea has become unrealistic. God's Word does not change, however, and the Bible tells us that sex outside of marriage is immoral (Matthew 15:19; 1 Corinthians 6:9, 6:13, 7:2; 2 Corinthians 12:21; Galatians 5:19; Ephesians 5:3).
Any person who has become a born-again Christian by putting his or her faith and trust in Christ no longer belongs to himself. First Corinthians 6:18-20 (NLT) says, "Run away from sexual sin! No other sin so clearly affects the body as this one does. For sexual immorality is a sin against your own body. Or don't you know that your body is the temple of the Holy Spirit, who lives in you and was given to you by God? You do not belong to yourself, for God bought you with a high price. So you must honor God with your body."
Disregarding God's plan for marriage, sex, and family always results in these kinds of spiritual or physical consequences: grieving the Holy Spirit (Ephesians 4:30), guilt, shame, regret, loss of respect for self and others, division in families and between believers, poor role modeling, pain for future spouses, unwanted pregnancies, abortion, and sexually transmitted diseases. God intends for sex to be an intimate expression of love and commitment, to be shared only between a husband and wife. Sex just for the physical pleasure of it damages our spirituality and pulls us away from fellowship with God.
Anyone who has made the mistake of having sex outside of marriage can be forgiven, even if the mistake results in an unplanned pregnancy. First John 1:9 says, “But if we confess our sins to him, he is faithful and just to forgive us and cleanse us from every wrong.” This does not mean that He will erase the consequences of our actions, but we can be restored spiritually by confessing and repenting from our sins. This means turning away from our sins and making the commitment to love and serve Christ.
There are some cases in which getting married before the baby is born would be wise. If a committed couple who was already planning to get married commits fornication which results in pregnancy, it would probably make it easier for the family and the child to marry before he or she is born. But if an uncommitted couple commits the same sin, getting married will not make them right in God's eyes. In such a situation, getting married will only set them up for marital failure. The Bible does not instruct people as to whether or not to marry under these circumstances, although both parents are still obligated to support the child emotionally, spiritually and financially.
None of us are made right with God through works. We are saved by faith alone, trusting in Jesus Christ to save us from our sins, which lead to death. The Bible says, "For the wages of sin is death, but the free gift of God is eternal life through Christ Jesus our Lord" (Romans 6:23). God does not want us to try to right our wrongs, but He wants us to give Him our hearts. By laying down our own will and submitting to the sovereignty of God, we can be assured of not only a fulfilling life on earth, but also a place in heaven for eternity.