1 Thessalonians 5:15
See that none render evil for evil to any man; but ever follow that which is good, both among yourselves, and to all men.
When Columbus was sailing over the Atlantic, believing there was another continent in the west, his men were dispirited and almost in mutiny, he said, "Unless we have some sign of land within the next three days, we will turn back." Fortunately, they had some signs of land, and the ships steered on until they came to the American coast. Now, what you are doing is good, and you should tolerate no "if" about it. You have been preaching, and teaching, and doing good for a long time, and perhaps you are ready to say, "Unless I have some signs of good fruit from my labour, I will give up." Do not. If that which you are following be really for the benefit of mankind, be not weary in well-doing. The test of success is not in numbers. Remember that Jesus had no disciples with Him in His trial; at His crucifixion He had only one, and He ended His beautiful ministry by the cross. Therefore, do not despair. Keep on with your work and keep at it. Persevere. Follow that which is good continuously unto the end.
Parallel VersesKJV: See that none render evil for evil unto any man; but ever follow that which is good, both among yourselves, and to all men.