Galatians 6:7-9,

7 Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap.

8 For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.

9 And let us not be weary in well doing: for in due season we shall reap, if we faint not.