I will cover you. And he offered a blood sacrifice, for blood had to be shed, in order to provide a covering for our first parents. And so God himself made a covering for our parents. The other one brings what God said was right, a blood offering. And God accepted the blood offering and rejected the one that was the product of man's own vain imagination.
Man is justified by a substitutionary death.
And this is taught throughout the Scripture. It is taught in the holidays, with Passover beginning with the substitute lamb who is slaughtered and whose blood is put on the door post of the house. And because of that blood, God passes over. I learn this from the Old Testament. Before I get to the New Testament, I can see all this.