From the Didache (early 2nd century), Chapter 1.
There are two ways, one of life and one of death; but a great difference between the two ways. The way of life, then, is this: First, you shall love God who made you; second, your neighbour as yourself; and all things whatsoever you would should not occur to you, do not also do to another. And of these sayings the teaching is this: Bless those who curse you, and pray for your enemies, and fast for those who persecute you. For what reward is there, if you love those who love you? Do not also the Gentiles do the same? But love those who hate you, and you shall not have an enemy. Abstain from fleshly and worldly lusts. If someone gives you a blow upon your right cheek, turn to him the other also, and you shall be perfect. If someone impresses you for one mile, go with him two. If someone takes away your cloak, give him also your coat. If someone takes from you what is yours, ask it not back, for indeed you are not able. Give to every one that asks you, and ask it not back; for the Father wills that to all should be given of our own blessings (free gifts). Happy is he that gives according to the commandment; for he is guiltless. Woe to him that receives; for if one having need receives, he is guiltless; but he that receives not having need, shall pay the penalty, why he received and for what, and, coming into straits (confinement), he shall be examined concerning the things which he has done, and he shall not escape thence until he pay back the last farthing. (Matthew 5:26) But also now concerning this, it has been said, Let your alms sweat in your hands, until you know to whom you should give.
Can you imagine what this world would be like if Christians lived up to this early standard?