...How would you feel if you went into a bakery, ordered catering from the owner for a special Sunday evening church service. You're given the order to sign, and after doing so, you remark that your church is grateful for the reasonable price, as you will be showing "Passion of the Christ" at the Sunday evening service he has just agreed to cater and hope to have several unchurched attend so they will hear the gospel. He surprises you by yanking back the paperwork and stating,, "I'm sorry, I didn't know this was a church service. I'm atheist, I don't associate with Christians, and I won't be able to cater the event for you." Unfair? Discriminatory? Of course it is. ...
Doesnt make any difference how I feel. I believe he has the right to refuse service for any reason.
But I might be going off OP - (and it wouldnt be the first time)
But if you had your choice of have a cater who is a Athiest or a fellow believer to cater your church dinner - who would you rather have - the athiest, so you can be a witness, or the Believer so you can finanically support a Chrisitan brother.