No, they should not. Church's are basically business' and should have the right to deny people from marrying in the church. The thing is, they would be stupid not to allow gay marriages. Getting married in a church is not free. In other words if the person in charge of the church says no to gay marriage in they church they are turning down money that would help the church.This question can apply to all places of worship, so mosques, synagogues, hindu temples etc.
Should places or worship be forced to accommodate for gay weddings?
That's why so many churches preach against elevating love of money to sin and evil. If a church would sell its Christian principles like that, it has no business being a church.