Galatians 6:9
 

⁹ And let us not grow weary while doing good, for in due season we shall reap if we do not lose heart.

 

2 Thessalonians 3:13
 

¹³ But as for you, brethren, do not grow weary in doing good.

 

1 Corinthians 15:58
 

⁵⁸ Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your labor is not in vain in the Lord.