Would there have been an uproar over as someone else stated "Jesus Christ is Lord and Savior" or "Shalom Aleikhem" or something to that effect?
If yes, then I say the teacher should be fired.
If that would also be fine to have the kids write, then I'm fine with it either way.
As long as it's fair to everyone and every religion (as the class is world religions). If it is not, then no one should be able to do it.