Sin is the condition into which all descendants of fallen Adam are born (Romans 5:12). Sin is living our lives independently of God. It's the result of being deceived by Satan to believe that meaning and purpose in life may be achieved apart from a personal relationship with, and obedience to, the Creator of life (Deuteronomy 30:19, 20; 1 John 5:12). In the non-Christian, sin permeates the old nature, dominates the old self, and perpetuates the deeds of the flesh. Satan is at the heart of all sin (1 John 3:8). He deceives people into believing a lie and counsels them to rebel against God.
When you received Christ you died to sin and its power to dominate you was broken. Satan and sin have not died; they are still strong and appealing. But you no longer have to sin because you are dead to sin and alive to God in Christ (Romans 6:11). You are not dead to sin because you consider it so; you consider it so because it is so. In Christ you have already died to sin.
Paul goes on to say that we are not to use our bodies as instruments of unrighteousness (verse 13). If we do, we allow sin to rule in our mortal bodies. For example, it is virtually impossible for someone to commit a sexual sin and not use his body as an instrument of unrighteousness, allowing sin to rule. Ask the Lord to reveal to your mind how you have wrongly used your body, especially sexually. Renounce that wrong use and then submit your body to God as a living sacrifice. It is your responsibility not to let "sin reign in your mortal body that you should obey its lusts" (Romans 6:12).
Loving Lord, I know that sin's power over me has been broken. Help me live today in the light of that truth by renouncing sin and submitting my body to You.