2 Corinthians 4:1
Therefore, being engaged in this service and being mindful of the mercy which has been shown us, we are not cowards.
2 Corinthians 4:16
Therefore we are not cowards. Nay, even though our outward man is wasting away, yet our inward man is being renewed day by day.
Galatians 6:9
Let us not abate our courage in doing what is right; for in due time we shall reap a reward, if we do not faint.
2 Thessalonians 3:13
But you, brethren, must not grow weary in the path of duty;
Hebrews 12:3-5
Therefore, if you would escape becoming weary and faint-hearted, compare your own sufferings with those of Him who endured such hostility directed against Him by sinners.