Augustine of Hippo — on 2Cor 3:6 (LETTER 140, TO HONORATUS 19)

“Therefore, you that fear the Lord, praise him, and that you may worship him, not as slaves but as free men, learn to love him whom you fear, and you will be able to praise what you love. The men of the Old Testament, fearing God, because of the letter which terrifies and kills and not yet possessing "the spirit which quickens," ran to the temple with sacrifices and offered up bloody victims. They were ignorant of what was foreshadowed by them, although they were a figure of the Blood to come, by which we have been redeemed.”