Romans 6:22
But now being made free from sin, and become servants to God, ye have your fruit unto holiness.
Christian service is toward God. We were once the slaves of death and hell - doing Satan’s bidding. But now, in Christ Jesus, we are servants to God. Our fruit is fruit unto holiness. And a Christian enjoying fellowship with God will bear fruit, more fruit, and much fruit - because that’s what God expects us to do.