1 Cor. 3:16, Do you not know that you are God’s temple and that God’s Spirit dwells in you?
This tends to be a common verse around this time of year as believers look at dieting and exercise more. It is also often used as proof-text against drinking or smoking or other behavior that adversely impacts our bodies. The verse is not about us individually, though... not really about your personal body. It is about the body of Christ, the church. The church itself is indwelt and energized by the Holy Spirit. We must take church-life seriously!
In addition to the church being indwelt by the Spirit, I might add that 1) It is God's work. 1 Cor. 3:9 says that the church is "God’s field, God’s building." 2) It was established by Christ. 1 Cor. 3:10 says "According to the grace of God given to me, like a skilled master builder I laid a foundation, and someone else is building upon it. Let each one take care how he builds upon it. For no one can lay a foundation other than that which is laid, which is Jesus Christ."
How do we fit into the church? Individual people are what the church is comprised of. As 1 Cor. 12:27 says, the church is "the body of Christ" and each of us, you and I, are "individually members of it." As that chapter suggests, we each have a part that God has given us within the body of the church. When the feet, hands, ears, and eyes (1Cor. 12:14-26) all operate as they should, doing their part, and encouraging one another, God is glorified and He is shown to the world.