In Romans 12:1-2, Paul urges us to offer our bodies as a living sacrifice to God. We are to break free from the patterns of the world around us and transform by the renewing of our minds. This opens our eyes to God’s will and it pleases Him.
Therefore, as a sacrifice to God, we don’t want to fill our bodies with things that can destroy our offering. For example, if I am giving a gift to someone special, I care for the item and wrap it in pretty wrapping paper or a nice bag. However, how often do we destroy our living sacrifice (our gift) to God by not eating or exercising right, smoking, drinking, listening to perverse music, watching shows filled with cursing and nudity, or worse. We should want our offering to God to be better than any other gift we have ever given. We should want to make this gift (our body) to be beautiful, clean, and pure.
Romans 12 (NIV)
"Therefore, I urge you, brothers and sisters, in view of God’s mercy, to offer your bodies as a living sacrifice, holy and pleasing to God—this is your true and proper worship. 2 Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is—his good, pleasing and perfect will."