'Reward' in the Bible

If any man's work comes through the test, he will have a reward.

But if I do it gladly, I have a reward; and if not, I am under orders to do it.

What then is my reward? This, that when I am giving the good news, I may give it without payment, not making use of my rights as a preacher of the good news.

Do you not see that in a running competition all take part, but only one gets the reward? So let your minds be fixed on the reward.