Faith never starts with what we believe; faith always starts with what He believes. Our part of faith is to come into agreement with, and simply rest in, and act on what He believes. Look at what God believes about the Christians relationship to sin.
Romans 6:5-7 NASB
[5] For if we have become united with Him in the likeness of His death, certainly we shall also be in the likeness of His resurrection, [6] knowing this, that our old self was crucified with Him, in order that our body of sin (our bodies as an instrument of sin) might be done away with (put out of business l), so that we would no longer be slaves to sin; [7] for he who has died is freed e from sin. …
Romans 6:10-11 NASB
[10] For the death that He died, He died to sin once for all; but the life that He is living , He is living to God. [11] Even so consider yourselves to be dead to sin, but living living to God in Christ Jesus. …
God believes that 2000 years ago the slave to sin, fallen self that you were, was crucified with Christ. He believes that in Christ you were taken to the place of execution, and the penalty of sin was paid for. As a result, the spiritual criminal you were, died, and therefore the new you is not under condemnation. He also believes that the serial sinner was killed in Christ, buried, and that a whole new you in union with the resurrected Christ rose from the grave into a whole NEW LIFE. He believes the new you in Christ is free from sins guilt and condemnation, and sins powers and enslavement.
God believes that Jesus’s death to sin, was your death to sin; and Jesus’s resurrection to a new life before God was your resurrection to newness of life before God. He believes that the godly life Jesus is living before the Father is your life, because you are in Christ. He knows you can choose to sin if you want to, but He knows that it is not your true nature anymore, and He knows that Jesus’s victory over sin is your victory over sin, and if you’ll just trust (thank Him for his victory in the moment of temptation) Jesus to manifest that victory, He will. In Paul’s words (who believed what God believed about him), “consider yourself dead to sin, but living to God, (because you are) in Christ Jesus.