God demands obedience from Christian in our thought life and in our souls, but this also requires us to be obedient in our physical bodies as well. Every decision we make is a spiritual decision. We must honor God in the way we treat and use our bodies.
Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; 20 you were bought at a price. Therefore honor God with your bodies. (I Corinthians 6:19-21 NIV)
The Apostle Paul states in this verse that our bodies are temples of the Holy Spirit. This is because those of us who have repented of our sins and believed in Jesus Christ have a relationship with God that unbelievers do not have. God’s Holy Spirit whom we have received from God is dwelling in us. God’s presence in our bodies is just as real as his presence used to be in the Holy of Holies in the Jewish tabernacle and in the temple. We do not own ourselves, either our bodies or our souls, for we are not our own, we have been brought with a price, the blood of Christ. Therefore the conclusion is obvious: we must honor God with our bodies.
This truth has many applications. It can be used as a valid argument against heavy smoking or drinking. But the immediate context is sexual immorality. There is perhaps no perhaps no way for us believers to dishonor God more with our bodies than by using them for sexual immorality, since we are, after all, temples of the holy spirit.