1 Corinthians 15:10

But I am whatever I am because of God's unearned favor, and the favor He showed me was not for nothing [i.e., Paul made the most of his conversion by being extra diligent in his service to God]. But I worked harder than all the other apostles, yet it was not I, but God's favor on me [that accomplished it].

1 Corinthians 15:58

Therefore, my dearly loved brothers, stand firm [in the faith]; do not be moved [from your commitment]. Always do your best to work for the Lord, since you know that your labor in the Lord's [service] is not for nothing.

Galatians 6:9

And we should not become tired of doing good things, for eventually we will receive [never ending life] if we do not give up.

Colossians 1:29

This is the reason that I work hard and struggle also, using God's mighty power which is at work in me.

Treasury of Scripture Knowledge

Summary

So we laboured in the work: and half of them held the spears from the rising of the morning till the stars appeared.

Bible References

So we

1 Corinthians 15:10
But I am whatever I am because of God's unearned favor, and the favor He showed me was not for nothing [i.e., Paul made the most of his conversion by being extra diligent in his service to God]. But I worked harder than all the other apostles, yet it was not I, but God's favor on me [that accomplished it].
Galatians 6:9
And we should not become tired of doing good things, for eventually we will receive [never ending life] if we do not give up.
Colossians 1:29
This is the reason that I work hard and struggle also, using God's mighty power which is at work in me.

General references

1 Corinthians 12:21
And the eye cannot say to the hand, "I do not need you," or again, the head [cannot say] to the feet, "I do not need you."
1 Corinthians 14:8
For if the trumpet gives an indistinct sound, who will get ready for a battle?