Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you? … For the temple of God is holy, which temple ye are (1 Cor. 3:16 – 17).
Our bodies are the temples of our spirits. Even though we choose what to do with them while we are here on earth, we must remember that they are sacred because Heavenly Father created them. President Gordon B. Hinckley said, “Our bodies … are the tabernacles of our spirits. He who is the Father of those spirits would have us build strength and virtue into these personal tabernacles.” …
President Boyd K. Packer, Acting President of the Quorum of the Twelve Apostles, said, “If you are well groomed and modestly dressed, you invite the companionship of the Spirit of our Father in Heaven and exercise a wholesome influence upon those around you. … Dress and groom to show the Lord that you know how precious your body is.”
Satan is jealous of everyone who has a body, because he cannot have one. He tempts us to ruin our body’s purity by wearing inappropriate clothing or taking harmful substances. He even tempts us to be ashamed of our bodies — -to think that they aren’t good enough, tall enough, strong enough, or pretty enough. If we follow the Spirit, we will be able to build “strength and virtue” into our bodies, and we won’t believe the devil’s lies about them. Heavenly Father is pleased with the earthly temples created for our spirits. We must show reverence for our bodies and treat them as holy temples.
Talk Source: http://www.lds.org/friend/2002/05/my-body-a-temple?lang=eng