a god that needs blood of innocent man on cross in order to forgive sins is unworthy of worship
Do you understand the concept of sacrifice is not blood upon the altar, but to give of yourself a valuable animal or possession to God?
When God asked Abraham to sacrifice his son, it wasn't about the killing or the blood; it was about Abraham being willing to give his most precious possession to God -- his own most precious and beloved son -- with no expectation of anything in return, but just to affirm his total trust in God.
True sacrifice is about giving to God what is valuable to us, with no expectation of return, as a mark of complete trust and faith in God. It's not about the blood on the altar, but it became so. The concept of sacrifice became corrupted and meaningless.
That is why Christ overthrew the tables of the money lenders in the temple, and eventually gave himself up willingly as the last and final blood sacrifice, to end forever the corrupted practice of blood sacrifice, to restore the meaning of the true sacrifice of Abraham -- of Abraham's willingness to give to God even the life of his own most precious son.
So, you see, it's a bit more complicated than your plain statements indicate, and of course the life and crucifixion of Christ hold many other messages and mysteries beyond this one alone.
However you are not expected to understand this