Galatians 6:9 "And let us not grow weary (ekkakeo, become useless) in doing good (kalos, good, valuable), for in due season we shall reap if we faint (ekluo, "throw in the towel") not."
2 Thessalonians 3:13 "But you, brethren, do not grow weary in doing good".
Matthew 23:1-5 "For they bind heavy burdens, hard to bear, and lay them on men's shoulders...but all their works they do to be seen of men". (Contrast Matthew 11:28-30), "Come to Me...take My yoke upon you.. My yoke is easy and My burden is light".
Micah 6:1-8 "O My people...how have I wearied you? ...He has shown you, O man, what is good; and what does the Lord require of you but... to walk humbly with your God"
Luke 18:1 "men ought always to pray and not to faint".
Hebrews 12:5-11 "do not despise the chastening of the Lord, nor faint (ekluo) when you are rebuked by Him".