"Do not rejoice in this, that the spirits are subject to you, but rather rejoice because your names are written in heaven." - Luke 10:20
One trap that Christians can fall into is successive service. Instead of rejoicing in our relationship with Jesus Christ, we measure ourselves based on what we do in the name of Jesus. The "what" becomes more important than the "who".
We also need to be careful of not screening people when they ask for help. Treat all people as God's creation, and not judging them on what they can do for you. Don't look down on somebody because they won't be able to somehow "elevate" you further in God's kingdom.