1 Faustus said: You ask if I believe the Old Testament. Of course not, for I do not keep its precepts. Neither, I imagine, do you. I reject circumcision as disgusting; and if I mistake not, so do you. I reject the observance of Sabbaths as superfluous: I suppose you do the same. I reject sacrifice as idolatry, as doubtless you also do. Swine's flesh is not the only flesh I abstain from; nor is it the only flesh you eat. I think all flesh unclean: you think none unclean.
Both alike, in these opinions, throw over the Old Testament. We both look upon the weeks of unleavened bread and the feast of tabernacles as unnecessary and useless. Not to patch linen garments with purple; to count it adultery to make a garment of linen and wool; to call it sacrilege to yoke together an ox and an ass when necessary; not to appoint as priest a bald man, or a man with red hair, or any similar peculiarity, as being unclean in the sight of God, are things which we both despise and laugh at, and rank as of neither first nor second importance; and yet they are all precepts and judgments of the Old Testament.
You cannot blame me for rejecting the Old Testament; for whether it is right or wrong to do so, you do it as much as I. As for the difference between your faith and mine, it is this, that while you choose to act deceitfully, and meanly to praise in words what in your heart you hate, I, not having learned the art of deception, frankly declare that I hate both these abominable precepts and their authors.
Source: Reply to Faustus the Manichaean (New Advent)