Sacrifices were offered in Faith of a Coming Saviour

By faith Abel offered God a better sacrifice than Cain did. By faith he was commended as righteous when God gave approval to his gifts. And by faith he still speaks, even though he is dead.

By faith Abraham, when he was tested, offered up Isaac on the altar. He who had received the promises was ready to offer his one and only son,

By faith he kept the Passover and the sprinkling of blood, so that the destroyer of the firstborn would not touch Israel’s own firstborn.