“Be careful not to practice your righteousness in front of others to be seen by them. If you do, you will have no reward from your Father in heaven. “So when you give to the needy, do not announce it with trumpets, as the hypocrites do in the synagogues and on the streets, to be honored by others. Truly I tell you, they have received their reward in full. But when you give to the needy, do not let your left hand know what your right hand is doing, so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you. Matthew 6: 1-4
There is a difference between doing a good deed and serving in the name of God. It's a fine line. We do not serve others in order that we might receive a special blessing. God does not operate a karma wheel.
When you give or serve because you are "supposed to do it", then you are working to please others or maybe even yourself instead of desiring to please God.
When you get the heart right, the service God exepects of us will follow naturally. This type of service is a fruit of walking in God's spirit.