'Reward' in the Bible

Now he who plants and he who waters are one; but each will receive his own reward according to his own labor.

If any man’s work which he has built on it remains, he will receive a reward.

For if I do this voluntarily, I have a reward; but if against my will, I have a stewardship entrusted to me.

What then is my reward? That, when I preach the gospel, I may offer the gospel without charge, so as not to make full use of my right in the gospel.