Do not think that nothing is wrong, simply because you do not see your growth, or you do not hear the hum of the engines. Great things grow in silence.

Galatians 6: 9
Let us not tire of doing good, because in due time we will reap if we do not give up.

2 Corinthians 9: 6
But this I say: He who sows sparingly will also reap sparingly; and he who sows bountifully will also reap bountifully.

Psalm 126: 5
Those who sow with tears will reap with shouts of joy.

Isaiah 40:31
But those who hope in the LORD will renew their strength; They will soar on wings like eagles, they will run and not tire, they will walk and they will not grow weary.

1 Corinthians 15:58
Therefore, my beloved brothers, stand firm, constant, always abounding in the Lord's work, knowing that your work in the Lord is not in vain.