The Bible’s answer
The Bible says that God’s will is for people to “abstain from sexual immorality.” (1 Thessalonians 4:3) As used in the Bible, the term “sexual immorality” includes adultery, homosexual acts, and sex between a man and a woman who are not married.
Why does it matter to God whether couples marry or not?
The marriage arrangement comes from God. He instituted it when he brought the first human couple together. (Genesis 2:22-24) He did not intend for a man and a woman to live together without the commitment of marriage.
God knows what is best for humans. He designed marriage to be a permanent union between a man and a woman that would benefit and protect all family members. Consider a simple illustration. Just as the instructions that come from the manufacturer show you how to assemble a piece of furniture correctly, God’s instructions tell us how to build successful family relationships. God’s standards always benefit those who follow them.—Isaiah 48:17, 18.
Sex outside of marriage can have serious consequences. For example, it can result in unwanted pregnancy, sexually transmitted diseases, and emotional turmoil.*
God gave men and women the ability to procreate by means of sex. God views life as sacred, and the ability to procreate is a precious gift. God wants us to treat that gift with respect by honoring his arrangement for marriage.—Hebrews 13:4.
What about living together before marriage to test compatibility?
How can couples build a strong marriage?
There are no perfect marriages. However, couples can build a successful marriage by applying the Bible’s advice. Here are some examples:
See the article “Young People Ask . . . What if I’m Being Pressured to Have Sex?”
See the article “Successful Families—Commitment.”