Sexual sin involves sinful sexual thoughts, words and actions with your body and/or another body. The foundational principle of overcoming sexual sin is based on the words of Jesus. Any thought of perversion concerning any woman or child or man is evil in the sight of God.

But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. (Matthew 5:28)

Where does sexual sin originate?

It proceeds from the sinful heart of man.

For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: (Matthew 15:19)

How does sexual sin harm a believer?

Here are three ways how sexual sin damages a believers spiritual life.

Loss of understanding

Sexual sin destroys Godly understanding in a person, it corrupts the soul. When we do not understand the consequences of our actions we often find ourselves in an unnecessary mess. Feelings of guilt, shame, rejection, loneliness, confusion, fear and similar spirits war against the soul. We cannot overcome these evil spirits with our strength. These evil spirits cloud our mind, inject thoughts contrary to the promises of God to lead us away from the narrow path into the broad way of life.

But whoso committeth adultery with a woman lacketh understanding: he that doeth it destroyeth his own soul. (Proverbs 6:32)

Unable to please God

It is the work of the flesh, the lust of the flesh. The Bible is explicit in its stating that it is good for a man not to touch a woman (1 Corinthians 7:1). Why? To avoid fornication. There was a time when a distance would be maintained, but in the guise of friendship and other convincing sounding arguments, the world has found itself lost in lust by the power of touch. The human physical senses are powerful with in-built indicators for man to recognise his own limitations. The conscience plays a critical role in helping us think twice about what we are doing. But, the lack of the fear of God drives man to lustful habits.

Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, (Galatians 5:19)

So then they that are in the flesh cannot please God. (Romans 8:8).

Desecration of the Temple of God

When we love God, we love Him with not only our mind and heart, but with all our strength as well, right? When we surrender ourselves in His Holy presence, don't we submit, the spirit, soul and body? Every part of us is precious in God's sight. He is holy, and He desires we be Holy as He is. What we think, say and do, matters to God. He can abide in us only if we abide in Him. While what we speak, sing, and do is critical, what we wear is also a fruit of the healing in our hearts. In a world of fashion and keeping up appearances, learn to overcome unnecessary indulgences and attractions that will hinder the work of God in our lives.

If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are. (1 Corinthians 3:17)