Galatians 6:7-9 (NIV)
Do not be deceived: God cannot be mocked. A man reaps what he sows.8 Whoever sows to please their flesh, from the flesh will reap destruction; whoever sows to please the Spirit, from the Spirit will reap eternal life. Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up.

Hebrews 12:1 (NIV)
Therefore, since we are surrounded by such a great cloud of witnesses, let us throw off everything that hinders and the sin that so easily entangles. And let us run with perseverance the race marked out for us.