The Didache, or Teaching of the Twelve Apostles (15.3-16.3)

And reprove one another not in wrath but in[*] peace as you find in the Gospel, and let none speak with any who has done a wrong to his neighbour, nor let him hear a word from you until he repents.

But your prayers and alms and all your acts perform as ye find in the Gospel of our Lord.

Watch over your life: let your lamps be[*] not quenched and your loins be not ungirded, but be ready, for ye know not the hour in which our Lord cometh.

But be frequently gathered together seeking the things which are profitable for your souls, for the whole time of your faith shall not profit you except ye be found perfect at the last time;

for in the last days the false prophets and the corrupters shall be multiplied, and the sheep shall be turned into wolves, and love shall change to hate;