Acceptable Sacrifices

Ut exhibeatis corpora vestra hostiam vivam, sanctam, placentem Deo, rationabile obsequiam vestrum.   Quia non homo ex eo quod vivit placet, sed placet ex eo bene vivet; nec ex eo fit homo hostia si se Deo offerat, sed si sancte offerat Deo. Quantum enim immaculata victima placat Deum, tantum Deum victima, si maculata fuerit, exacerbat. Audi dicentem Deum: Non offeras mihi claudum, non lusum, non mortis contagione pollutum, sed maturum sine macula. Hinc est quod Apostulus vivam Deo petit hostiam. Probat hoc Cain, qui cum Deo parva a quo totum perceperat ingratus pontifex sic divisit, ut quod erat pessimum, hoc adoleret altari; quod erat optimum, in suam reservaret offensam; denique cum sua suo male partitur cum auctore, se suosque posteros et a vita et ab humano genere perdivisit. Ergo Abel sequamur ad praemium, non Cain comitemur ad poenam. Abel agnum portans ad Dei sacrificium, sicut agnus assumitur: Cain gestans sibi stipulam, fomentum sibi, per quod exureretur, invenit. Sanctus Petrus Chrysologus, Sermo CIX

'That you present your bodies as a sacrifice, living, holy, pleasing to God.' 1  Because man does not please by the fact that he lives, but that he lives well. He does not offer a sacrifice of himself to God unless he offers himself to God in a holy manner. As much as an unblemished victim pleases God, so a spotted victim makes God angry. Hear God saying, 'Do not offer me a lame thing, or something half blind, or polluted because it is intended for death, but something mature without blemish.' 2 Hence it is the Apostle seeks a living sacrifice for God. Cain gives proof of this; he who as an ungrateful priest shared so few of his possessions with God, from whom he had received everything, that he offered the worst of them upon the altar, since what was best he kept for himself, and so offended. Thus wickedly arranging this division with his Creator, he separated himself and his descendants from life and from the human race. Therefore let us follow Abel to reward and let us not accompany Cain to punishment. Abel bringing a lamb to sacrifice to God was accepted as a lamb; Cain, bearing his stubble, found it to be kindling for himself, by which he was to burn. Saint Peter Chrysologus, from Sermon 109 1 Rom 12.1 2 Lev 22.20