Ephesians 6:8
because you know that the Lord will reward each one for whatever good he does, whether he is slave or free.
What it says
Knowing that whatever good anyone does, this he will receive back from the Lord, whether he is slave or free.
What it is doing
It places service before the Lord's reward.
In context
5Slaves, obey your earthly masters with respect and fear and sincerity of heart, just as you would obey Christ. 6And do this not only to please them while they are watching, but as servants of Christ, doing the will of God from your heart. 7Serve with good will, as to the Lord and not to men, 8because you know that the Lord will reward each one for whatever good he does, whether he is slave or free. 9And masters, do the same for your slaves. Give up your use of threats, because you know that He who is both their Master and yours is in heaven, and there is no favoritism with Him.