Original Sin, Cain's Religion vs the Blood Gospel

Original Sin occurred in the Garden of Eden, and the Lord God Jehovah gives us all an example of blood sacrifice for sin when He covered Adam and Eve in animal skins (pelts). Later, Cain thought he could do his own sacrifice by giving some crops of the field, and was rejected of God. Abel gave an animal sacrifice, thus pointing toward the future sacrifice of Jesus Christ on the cross. Are you going the Bible way, and trusting the blood of Christ?