Since you are not entirely sure about what to do, and don't have a lot of the Hail Mary fabric, I have another possible suggestion. I'd do the back of the original quilt in something neutral that would be acceptable to any denomination or religion. After all, you want to make the most money you can off of this raffle, and not deter any perspective buyers. If you have the time or are inclined to do so, how about using the Hail Mary fabric for a baby quilt or for a youth size suitable for a first communion gift? I am sure it would sell and you'd know that the buyer and/or recipient would appreciate the text. Just a thought.