Ok, Christ wasn't payment for our sins. I'll go along with that. All knowing God uses the free will of the people(in your opinion) to kill His son. If this is to be considered a debt remittance then what you have is God paying Himself. No, but I've carried live turtles from one side of the road to the other just to avoid them being killed crossing. However I'm not aware of anything significant about my act other than denying a turtle the chance to die unnaturally.