In order to attain victory over sin we must know, believe, and apply the wonderful truths of the gospel of our salvation. So then we must know the gospel, believe the gospel, and apply the gospel if we are to attain victory over sin. We do not possess the ability to overcome sin in ourselves. We cannot use the Law to overcome sin because we are sinners and therefore the Law arouses sin in us rather than arresting sin in us. We cannot use license as an excuse to continue in sin because that defeats the whole purpose of the gospel in the first place. The purpose of the gospel is to give victory over sin and transform self-loving sinners into God-loving saints.
Since neither Law nor license gives a remedy for sin and since we do not possess the ability to overcome sin in ourselves, God has granted to us everything we need pertaining to life and godliness, through the true knowledge of the gospel of the Lord Jesus Christ, so that we might become partakers of the divine nature and escape the corruption that is in the world by lust (see 2 Peter 1:3-4). The Lord Jesus put it this way, "You will know the truth, and the truth will make you free" (John 8:32).
Christian living is based on Christian learning; Christian devotion is based on Christian doctrine; Christian behavior is based on Christian belief. Each of these statements is another way of saying the truth that sanctification is based on justification. So if we are going to have victory over sin then first and foremost we must be saved - justified. And then we are to take the reality of our justification and make progress in our sanctification. Our progress in sanctification is not by works of the Law. We do not begin in the Spirit and then become perfected by the flesh (Galatians 3:3). Our progress in sanctification is still by faith - knowing, believing, and applying the truth of the gospel to our lives.
This is what Paul is talking about in Romans 6:1-23 in order that Christians can attain victory over sin and live lives that are pleasing to the Lord in all respects and to walk in a manner worthy of the Lord and of His gospel.
Paul gave three instructions for attaining victory over sin in Romans 6:1-23. We will only consider two of them as found in Romans 6:1-11 at the present and then we will cover the last one as found in Romans 6:12-23 at a later date.
The first instruction for attaining victory over sin is "know" (Romans 6:1-10). Paul repeated the word "know" three times in Romans 6:1-10 - 3, 6, and 9. Paul wanted the Christians at Rome to know basic doctrine because he knew that behavior always flows from belief and that sanctification always flows from justification. This is why Paul wanted his readers to know and understand justification because in and through that would flow their sanctification.
The basic doctrine Paul wanted Christians to know was their identification with Christ in death, burial, and resurrection as illustrated in baptism. Just as we are identified with Adam in sin and condemnation through virtue of being born into his family with him as our federal head and representative, so we are now identified with Christ in righteousness and justification by virtue of being born again into his family with Him as our federal head and representative. Through our new birth we are children of the King and this knowledge believed should control how we behave. But the apostle went even deeper than this truth to show what happened to us in Christ Jesus to show that it is an impossibility to be justified without sanctification flowing from it.
So Paul took the truth of the gospel - the death, burial, and resurrection of Jesus and our identification with Him in those events to establish two major truths that when known will affect how we behave and will give us victory over sin.
Know that we are dead to sin (6:1-7).
We are dead to sin through identification. We know the gospel - that Christ died for our sins according to the Scriptures, and that He was buried, and that He was raised on the third day according to the Scriptures (1 Corinthians 15:3-4). So if Christ's death was for my sins then his death was for me, His burial was for me, and His resurrection was for me.
"Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death?" (Romans 6:3). The Holy Spirit of God identified us with Christ when He baptized us into Christ at our conversion. The Holy Spirit made the death of Christ real to us and made it not only His death but our death. In substitution Christ died for my sins; in identification I died with Him. In substitution Christ died unto sin (Romans 6:10a); in identification I died unto sin (Romans 6:2-3).
"Therefore we have been buried with Him through baptism into death..." (Romans 6:4a). The Holy Spirit of God identified us with Christ's death and His burial. The Holy Spirit makes the burial of Christ real to us and makes it not only His burial but our burial. Burial is for the dead not the living and so the death of Christ was real because the burial of Christ was real and through identification with Him our death and burial are real because we deserve it and He didn't. So through identification when we look on the death and burial of Christ we understand and confess that what He did was substitutionary - that we deserve it and He didn't so that it was for us and not for Him.
In order for Christ to die and be buried there had to be something instrumental in His death. "Knowing this, that our old self was crucified with Him, in order that our body of sin might be done away with, so that we would no longer be slaves to sin; for he who has died is freed (acquitted) from sin" (Romans 6:6-7). So not only are we identified with Christ's death and burial we are also identified with His crucifixion. Those were my nails he took; that was my crown of thorns he wore; and those were the stripes due to my back that he endured!
We are dead to sin through illustration. Our water baptism illustrated our death and burial to sin and resurrection to walk in newness of life under loving loyalty to Jesus as Lord (Romans 6:4-5).
Know that we are alive to God (6:8-10)
We are alive to God through identification. The resurrection of Christ was based solely on His righteous life and character. Since His death and burial were substitutionary then His resurrection was necessary! However, it is based on His resurrection that we are able to be justified (Romans 4:25 and 1 Corinthians 15) and that He can now be the Lord of our lives giving us His presence through the Holy Spirit as a new life principle (Romans 6:4b-5). We are longer alive to sin and dead to God but we are now dead to sin and alive to God through Jesus Christ our Lord.
Since we are dead to sin by identification with the death and burial of Christ then we are also alive to God by identification with the resurrection of Christ.
We are alive to God through illustration. Our water baptism illustrated our death and burial to sin so that it declares that we are dead to sin and resurrection to walk in newness of life so that it declares that we are alive to God (Romans 6:8-10).
The second instruction for attaining victory over sin is believe (Romans 6:11). Your translation might say "consider" "count" or "reckon." "Reckon" doesn't mean "to think" or "to guess." It means "to put to one's account." It simply means to believe what God says in His Word is really true in your life concerning your salvation. We are to act on God's Word and be doers of it and not just hearers. We are to behave because we believe. We believe that we are dead to sin and alive to God so we should practice it and not just preach it.