"I understand what the teacher is trying to portray here. "
Nope, you don't understand. The teacher is trying to make people step on piece of paper with the name Jesus on it. Period. The rest is camouflage.
" I am sure the point could have been made without singling out a particular group."
Nope. The point is to single out a particular group: Christians.
If you are going to be an adult, you are going to have to look at what liberals do and not listen to what they liberals say.