The idea that salvation requires a blood sacrifice to appease God is actually a relatively late development in Christian thought, becoming dominant mainly during the Protestant Reformation. Earlier Christians, including many Church Fathers, understood salvation differently.

As Delores Williams points out, if we believe God is love (1 John 4:8), how can we reconcile that with a God who demands blood sacrifice - even of his own child - to forgive? Jesus himself repeatedly emphasized that God desires mercy, not sacrifice (Matthew 9:13, 12:7). He taught that the father in the prodigal son story forgave freely, without requiring payment or sacrifice.

Your example of the Samaritan woman actually supports this view - she was transformed by encountering Jesus's way of living and loving, not by his death. She hadn't yet heard of his crucifixion when her life was changed.

Christianity is indeed unique - not because it requires blood sacrifice (many ancient religions had that), but because it presents a God of unconditional love who shows us through Jesus how to live in right relationship with God and neighbor. That's the true gift of righteousness.