Romans 5: (ESV)
3 Not only that, but we rejoice in our sufferings, knowing that suffering produces endurance, 4 and endurance produces character, and character produces hope, 5 and hope does not put us to shame, because God's love has been poured into our hearts through the Holy Spirit who has been given to us.
James 1:12 (ESV)
Blessed is the man who remains steadfast under trial, for when he has stood the test he will receive the crown of life, which God has promised to those who love him.
Galatians 6:9 (ESV)
And let us not grow weary of doing good, for in due season we will reap, if we do not give up.