Christian service isn't only in the practical aspects of ministry (sweeping floors, church set up, etc.) but also in financial giving. Towards the end of Acts 4 we see a man named Barnabas, the son of encouragement. He wholeheartedly sold his property and gave the proceeds to support the Church. In Acts 5, Ananias and Sapphira also gave financially to support the Church, but they were doing it with the wrong heart. The same can be said about practical ministry at Church. We are able to have much accomplished - but are the motives of our hearts right with God?
In the letter to the Philippian Church, Paul commends them because they had provided for his necessities as he went through to share the gospel in the city of Thessalonica. He commends them not because he wants more from them, but so that fruit may abound to their account - in essence, so that God may bring about growth in their lives as Christians.
If we suspect that we have the wrong attitude in our service, our immediate response shouldn't be to stop serving. Rather, we should keep on serving while all the while praying that God works in our hearts to give us joy in serving.
Colossians 3:23, 25 - 'Whatever you do, do it heartily as to the Lord and not to men, knowing that from the Lord you will receive the reward of the inheritance; for you serve the Lord Christ.'