The reason lesbianism and homosexuality are sinful as acts or lifestyles (along with bisexuality, multisexuality, pansexuality, omnisexuality, etc.) is because they run contrary to God’s plan, design, and created order.
When God created Adam and Eve, He united them in marriage, made them one flesh, and told them to be fruitful and multiply. These facts, combined with God’s intricate and intentional design of their physical bodies, testify to His intention for sex, marriage, procreation, and the family unit.
There is not one instance in Scripture where God approved of or condoned a romantic relationship, sexual act, or marriage between two people of the same biological sex or gender. The only marital union God ever established is between one biological man and one biological woman for a lifetime. Likewise, the only sexual intimacy ordained and blessed by God occurs between a biological man and a biological woman within marriage. Anything outside of those biblical parameters is sinful.
One of the most explicit proofs of God’s disapproval of lesbianism and homosexuality is found in Genesis, chapter 19. God destroyed the cities of Sodom and Gomorrah because they were filled with people committing gay acts and orgies. God told Abraham if He found as few as ten righteous people in Sodom, He would spare the entire city for their sake. Given that God brought destruction upon those cities and their inhabitants the following day, it clearly established gay practices as sinful.
Despite God's disapproval of gay lifestyles, there is always hope for those who practice it to break free from the cycle of sin and bondage. First, they must acknowledge their sinfulness before God, turn away from it (repent), and trust Jesus for their salvation and redemption. When this occurs, God graciously gives them a new, godly nature and forgives them completely — washing them white as snow. He also sends the Holy Spirit to live inside them to transform them from the inside out. However, if gay individuals choose to remain in their sinful state, they will forever be enslaved by their sinful nature and reap physical and spiritual death in the end.
