Where does it say in the Bible that Old Testament believers need only to believe in the coming redeemer to be saved. Also, how does that correlate with animal sacrifices. Does it mean as long as they believed, they really did not have to sacrifice?
The Old Testament never says that people of that period had only to believe in the coming redeemer to be saved. What it does imply, in places like Psalm 51:16-17, Isaiah 66:2-4, Micah 6:6-8 and others is that without belief in a coming redeemer the offering of sacrifices was futile. Salvation in the Old Testament required both obedience to the Law and belief in a coming redeemer, since their sacrifices could only set aside their sins until the redeemer came to pay for them.