Have not I commanded thee? Be strong and of a good courage; be not afraid, neither be thou dismayed: for the LORD thy God is with thee whithersoever thou goest.- Joshua 1:9

Wait on the LORD: be of good courage, and he shall strengthen thine heart: wait, I say, on the LORD. Psalms 27:14

He giveth power to the faint; and to them that have no might he increaseth strength.- Isaiah 40:29

No weapon that is formed against thee shall prosper; and every tongue that shall rise against thee in judgment thou shalt condemn. This is the heritage of the servants of the LORD, and their righteousness is of me, saith the LORD.- Isaiah 54:17

A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.- Ezekiel 36:26-27

For which cause we faint not; but though our outward man perish, yet the inward man is renewed day by day. For our light affliction, which is but for a moment, worketh for us a far more exceeding and eternal weight of glory; While we look not at the things which are seen, but at the things which are not seen: for the things which are seen are temporal; but the things which are not seen are eternal.- 2 Corinthians 4:16-18

And let us not be weary in well doing: for in due season we shall reap, if we faint not. Galatians 6:9

I can do all things through Christ which strengtheneth me.- Philippians 4:13