Hmmm. You've edited extensively since I first read your post, so I'll have to revise what I intended to say in my response to address the issues you've elaborated on.
I understand your objection to a sacrifice "magically" absolving one of sin. I'm not going to pretend to understand exactly how Jesus' death on the cross "works." I'm not a theologian and throughout the history of Christianity the great theologians of the faith have never come to a consensus on exactly how that works. For our purposes, I will simply say that something about Christ's sacrifice sets right the broken relationship between God and human beings. I think most Christians would agree to that at least though the how is subject to much debate. Of course, I imagine the finer points of theology would be of little interest to you. You're probably more interested in what Christians take from this belief when it comes to how it applies to how we relate to others. What I would say in that regard is that a Christian does not believe that the absolution offered by Christ somehow absolves the Christian of any responsibility or accountability for their actions. Most Christians will insist that a person should still receive the consequences for their actions even if Jesus has forgiven them.
Your definition of sin is not the same as most Christians, I think. You'll hear a lot of definitions from Christians of various stripes ranging from "breaking God's law" to "seperation from God" to "anything that hurts someone else." At any rate I don't think any Christian is going to argue that forgiveness from God or another person excuses wrong behavior or means that you are no longer responsible for your actions. A person can absolutely be "absolved of their sin by becoming a good Christian but still be responsible for their past actions." I should further add that many Christians assert that it is the acceptance of Jesus death on their behalf that leads to a transformed life--where the old wrong actions are let go of and the person leads a more moral life. They do not believe that accepting Jesus is "get out of jail free" card that allows them to do whatever they like without consequences either here or in eternity.
As for the issue of forgiveness, Christianity is certainly not the only religion that teaches forgiveness, and indeed I'm sure there are many non-religious people who espouse it's value a;sp. Again, if you assume the forgiveness equals excusing wrong behavior, then I don't think you correctly understand what forgiveness is. Correctly understood, forgiveness can not be a burdensome expectation placed on a victim. It'd be interesting to hear you make the argument that holding on for a lifetime to the hurt, bitterness, rage etc is to the victims benefit and will help them heal. Forgiveness is about freedom for ones self, not making the perpertrator feel good.
My thought too.
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