You definitely want your sales team to understand what the purpose of church fundraising is, but that doesn't mean you have to focus solely on the statistical aspects of how much things cost and how much money you do or don't have. For your church fundraiser to get off on the right foot, begin by talking about working as a team, and how by working hard on church fundraisers, you will be able to continue to provide a spiritual home for your community of people doing God's work. The youth group will be able to do things, the choir will be able to purchase music and replace their robes, and you could even fund things like mission trips.
People will work harder for something if they see the positive aspects of it, and they will definitely throw their best effort into your church fundraisers if it is enjoyable as well as profitable. This is an opportunity for you to show the community at large what kind of great work the church does, and how they can help you to make the church even stronger and more important to the community than it already is. So get your group fired up about the fantastic work they're about to do, and in turn you will see that your church fundraisers are more successful than you could have imagined.