'Reward' in the Bible

Now the one planting and the one watering are one in purpose, and each will receive his own reward according to his own labor.

If anyone’s work that he has built survives, he will receive a reward.

For if I do this willingly, I have a reward, but if unwillingly, I am entrusted with a stewardship.

What then is my reward? To preach the gospel and offer it free of charge and not make full use of my authority in the gospel.