1 Corinthians 6:19-20 KJV
What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a PRICE: THEREFORE glorify God in your body, and in your spirit, which ARE God's.
Why do we forget this? I don't mean this in the manner of eating and being healthy which that is also another aspect of letting God use our bodies.
But we neglect to keep it a Holy place for Him when we use it for things of the world. When we rely on relationships that are more of a physical nature outside of the boundries of what God intended in His word, we are not living under Kingdom principles as we may think, even though we are trusting in Him.
He wants what He is residing in to be kept pure and Holy for His purpose. We have been bought with a price of Christ's death on a Cross. The things of the world can not partake of our bodies when we are asking Christ to reside in us. It isn't going happen.
God created us for His pleasure and for His fellowship. To put it bluntly keep in mind that when satan was trying to give Christ the kingdom of earth, it was only in his hands until Christ took it from him at His resurrection. satan is decieving us into thinking he still has it, but Christ took it over. Therefore, its is in Christ's hands not satans. However, when we sin we have turned our backs on Christ and what He has done for us. Our bodies can not live in the Kingdom of Heaven with sin on its heart. We are the ones that make the choice to reign with God and fellowship with Him fully with all we have of ourselves as a pure spotless bride.
And to be a pure spotless Bride we need to keep our bodies pure for Him, and live under the guidlines of His Word, as they are written as a guide in living in the Kingdom.