H/T Divineoffice.org From a letter attributed to Barnabas The new law of our Lord
God has abolished the sacrifices of the old law so that the new law of our Lord Jesus Christ, which does not bind by slavish compulsion, might have an offering not made by man. On another occasion he says to them: When I brought your forefathers out of Egypt, I gave them no commands about burnt offerings and sacrifices. I said not a word about them. What I did command was this: Do not contrive any evil against one another, and do not love perjury.
We are not stupid; surely we ought to understand our Father’s kindly purpose in this. He does not want us to go astray as they did, nor to ask how we are to approach him. Here is what he says to us: The sacrifice acceptable to God is a broken heart; the fragrance pleasing to the Lord is a soul that gives glory to its Maker. You see, my brothers, we must carefully seek after our own salvation; otherwise, one who is bent on deceiving us will insinuate himself and turn us aside from the path that leads to life.
God spoke of this once again when he said to them: On such a day you are keeping a fast that will not carry your cry to heaven. Is it that sort of fast that I require, a day of mortification like that? But to us he says: Is it not this that I demand of you as a fast—loose the fetters of injustice, untie the knots of all contracts that involve extortion, set free those who have been crushed, tear up every unjust agreement. Share your food with the starving; when you meet a naked man, give him clothing; welcome the homeless into your house.
Accordingly, we must flee from all vanity and show an utter hatred for the deeds of the evil way. Do not turn inward and live only for yourselves as though already assured of salvation; join together rather and seek the common good. For, as Scripture says: Shame on those who are wise in their own judgment and think themselves clever. Rather, let us become spiritual; let us be a perfect dwelling place for God. As far as we can, we should dwell upon the fear of God and strive to keep his commandments, finding our delight in his observances. The Lord will judge the world without respect to persons; everyone will receive his just deserts; if he has been good, his good works will go before him; if wicked, the wages of sin will lie in wait for him. We must never relax our efforts as though our calling were already realized. Never let us fall asleep in a state of sin, lest the prince of wickedness gain power over us and snatch us away from the kingdom of the Lord.
My brothers, grasp this further point: You see the Israelites rejected, even after the many signs and wonders worked among them; let us then see to it that we are not found among those of whom Scripture says: Many are called, but few are chosen.