Paul begins with a question: shall we sin so that grace may abound? He answers with a firm no. Those who have died to sin cannot go on living in it. All who were baptized into Christ Jesus were baptized into his death, buried with him so that, just as Christ was raised by the glory of the Father, they too might walk in newness of life.
If they have been united with him in a death like his, they will be united with him in his resurrection. Their old self was crucified with Christ so that the body of sin might be brought to nothing and they would no longer be enslaved to sin, because the one who has died has been set free from sin. Christ, raised from the dead, will never die again; death no longer rules over him; he died to sin once for all and lives to God. So believers must consider themselves dead to sin and alive to God in Christ Jesus.
From that come the exhortations: do not let sin reign in your mortal body, do not present your members to sin as instruments of unrighteousness, but present yourselves to God as those brought from death to life and your members as instruments of righteousness. Sin will have no dominion over them, because they are not under law but under grace.
Paul asks the question again and again answers no. Everyone is a slave of the one they obey, either of sin leading to death or of obedience leading to righteousness. The Romans were once slaves of sin, but they obeyed from the heart the pattern of teaching to which they were committed and, set free from sin, became slaves of righteousness. The fruit of that life leads to sanctification, and the end is eternal life. For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.