Let me ask you a question...
If you asked God for an answer or something and have not received is it because of your righteousness or holiness?
99% of people will say because of righteousness with God, (right standing between you and God)
and therefore they try to do good works, sing in the worship team, serve as ushers or get involved to earn and use that as a motivation to serve in God's kingdom
Here is the thing. We cannot earn righteousness through good works and faithfulness. (2Cor5:21 God made him who had no sin to be sin for us, so that in him we might become the righteousness of God.) First we need to accept Christ as our Lord and Savior and then by God's grace we become righteous.
Righteousness cannot be earned, so when we think we will work for righteousness it is dead works. Righteousness is a gift from God.
So how do I receive from God and what should my motivation be to serve?
According to Matthew 21:22 when we pray and ask God for something and believe, we have received it.
So when you asked and believed, you have received it and therefore you serve God out of love because you have already received it.
LOVE SHOULD BE YOUR MOTIVATION.
Why do you serve?