2 Corinthians 4:1
So, because I hold a place in this ministry and that because I have had God's mercy shown me, I never give up.
2 Corinthians 4:16
So I never give up; instead, although my outer nature is wasting away, my inner nature is constantly renewed from day to day.
Galatians 6:9
Let us stop getting tired of doing good, for at the proper time we shall reap if we do not give up.
2 Thessalonians 3:13
But you, brothers, must never grow tired of doing right.
Hebrews 12:3-5
Yes, to keep from growing weary and fainthearted, just think of the examples set by Him who has endured so great opposition aimed at Him by sinful men!