In Romans 6 he is saying we are dead to sin. Therefore do not sin.In Romans 6 he is talking about what one should be, that sin should be dead
Being made dead to sin, we are admonished to not sin.
Romans 6:3-14 KJV
3) Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
4) Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
5) For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
6) Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
7) For he that is dead is freed from sin.
8) Now if we be dead with Christ, we believe that we shall also live with him:
9) Knowing that Christ being raised from the dead dieth no more; death hath no more dominion over him.
10) For in that he died, he died unto sin once: but in that he liveth, he liveth unto God.
11) Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord.
12) Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof.
13) Neither yield ye your members as instruments of unrighteousness unto sin: but yield yourselves unto God, as those that are alive from the dead, and your members as instruments of righteousness unto God.
14) For sin shall not have dominion over you: for ye are not under the law, but under grace.
Having died to sin, we are to reckon ourselves dead (why?), and we are to not let sin rule in our mortal bodies. We we have to reckon ourselves dead to sin, are we really dead to sin? Wouldn't it be a given that we are dead to sin? But we are told to reckon it.
Being dead to sin, we are told, don't let sin rule in your body (body?). But if we are dead to sin, doesn't that make this moot? Being dead to sin, we are told to not yield our "members" (body parts) to sin. But if we are dead to sin, how could we?
These questions have no answer if being crucified with Christ, being raised with Him, being dead to sin, meant that we were completely done with sinning. But if rebirth is in a new creation spirit, while we still live in corrupt bodies, in which sin still lives, all of this is completely understandable.
Much love!