As i'm posting right now i receive an email reminding me about the outing the church has tonight and they want me to be at the church an hour before we go out so we can go over the music... I feel like they are taking advantage of me i can stay home and play with some cd and be blessed.
Even if it is true that they are taking advantage of you, now is not the time to make a stand. If you are a part of the music ministry that is to perform tonight, you need to deliver on that responsibility.
But you do have to decide if this is something you want to remain committed to and advise them accordingly as soon as you have made such a decision.
Whether a musician wants / needs to be paid for services is a personal thing, combined with the culture of the church being serviced. Some churches pay well and demand a lot. Some churches take whatever they get and just want somebody who'll show up. Others project an air suggesting they think you owe them for the privilege to be seen in their sanctuary. Your gifts may very well come from God, but they are yours to develop and hone and yours to share in the manner you deem most appropriate. If you are willing to play for no pay, go for it. If you think you should be paid, ask for it.