The strength of sin is that we come to accept sin is washed away by sacrifice and tithes and paid off and foriven and forgotten,...
Actually, the power of sin being the law means the law acts like a marriage contract that holds us in bondage to the desires of sinful flesh. Not until the sinful flesh dies with Christ on the cross are we set free from the bondage of the flesh that the law kept us in marital bondage to:
"the law has authority over someone only as long as that person lives? 2 For example, by law a married woman is bound to her husband as long as he is alive, but if her husband dies, she is released from the law that binds her to him. 3 So then, if she has sexual relations with another man while her husband is still alive, she is called an adulteress. But if her husband dies, she is released from that law and is not an adulteress if she marries another man.
4 So, my brothers and sisters, you also died to the law through the body of Christ, that you might belong to another, to him who was raised from the dead, in order that we might bear fruit for God. 5 For when we were in the realm of the flesh, the sinful passions aroused by the law were at work in us, so that we bore fruit for death. 6 But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code.
7 What shall we say, then? Is the law sinful? Certainly not! Nevertheless, I would not have known what sin was had it not been for the law. For I would not have known what coveting really was if the law had not said, “You shall not covet.” 8 But sin, seizing the opportunity afforded by the commandment, produced in me every kind of coveting. For apart from the law, sin was dead." (Romans 7: NIV)
Read it carefully and thoughtfully and you'll see that's exactly what Paul is saying the 'power' of the law is. It's the power to keep us bound to sinful flesh...as long as sinful flesh is alive. That's why sinful flesh must die with Christ on the cross, so we can be joined in marital bondage to Christ through the new way, the new marital contract
of the Spirit and held fast in bondage to righteousness by that contract. Pretty cool stuff if you ask me.
(Note that the example of sin that he uses is not a dead cycle of repeated sacrifices and worship--as true as that fundamental point surely is, but of
coveting.)