In these verses sin is conceived metaphorically as a master or king who may be allowed to reign (basileuetō) in the body of the believer, demanding obedience to his wishes. Believers may either present the members of their bodies to sin to be used as weapons (hopla) of unrighteousness (cf. 2 Cor. 6:7; 10:4; Rom. 13:12); or they may present themselves to God and their members as weapons of righteousness.

If Paul has Israel’s political situation and the military strength of Rome in the back of his mind, the weapons metaphor may be more than incidental.

Paul constructs this choice as an exhortation (Let not sin, therefore, reign…), on the grounds that at some point in the future sin will not be lord (kurieusei) over you. This appears to have in view a moment when sin will be lord (because ‘sin came to reign in death’: 5:21) but not over those who are ‘dead to sin and alive to God in Christ Jesus’ (6:11). The reason is that they are not under Law but under grace, which again reminds us that this is at its heart an argument about Israel. It is Paul’s contention in Romans that the Law ‘brings wrath’ (4:15) because of the prevalence of sin and that escape from the condemnation of the Law, which would be realized concretely in the war against Rome, is to be achieved through the grace of God which abounded in the obedience and faithfulness of the one man Jesus Christ (5:15-21).