No offense, but if I was the teacher of this Religion class, I would not give anything higher than a C or maybe a C+ to any of the ideas so far.
The project is not "use magic to show a small demonstration of something small about one specific religion." The project is, "use a medium to express a religion." The teacher is looking to see how his/her students grasped the concepts behind the various religions, and testing to see if the students can express those concepts in a creative way.
The idea behind using magic as this "medium" is good, but it is SECONDARY to what needs to be expressed. Going off and just showing a sponge ball routine to represent "feeding the multitudes," is only grasping one very very small aspect of the project. If anything, the magic trick needs to express a Christian's faith in the miracles of Christ, the resurection of Christ, the Holy Trinity, as those are the defining characteristics of Christianity.
One way around this though, and it will be a lot deeper, is expressing how the general Christian multitude sees magic as the "devil's work." In a sense, you will be expressing your "frustration" with the hypocricy that some Christian's represent. Being able to express present day values of the Christian church should be just as acceptable as expressing traditional beliefs (if the teacher is good that is).
If you wanted to do this, you could created a story like....
"I was at a church picnic one day with my deck of cards, and I was showing some tricks to some friends, when one of the Youth pastors took me aside, and asked me if I believed in the devil and witchcraft, bla bla bla..." and go on to say how he disapproved of your hobby... and how this frustrated you... bla bla bla, then you used that youth pastors logic to start having doubts about the christian faith... (this is where the magic comes in)... Now, you can do something like... "WHen I was young, I believed in magic, until someone showed me how something was done.... for a while, my faith was dead, I was sad and disappointed, but then I started to appreciate the art of deception and sleight of hand..." etc.... go into and even reveal a simple sleight to the class...
at the end, your conclusion can be... "Christianity, to many around the world is an unwavering faith... until the sleights are revealed, after that, to the newly born atheist... it is nothing more than deception and very well performed 'sleights', like the tricks I showed you just now."
The End.
p.s. I am Christian, but his something that was said to me before... and I am a university teacher, so I know what teachers are looking for.
If you have further questions, please PM me.