Mark said some things the other day that I didn't respond to because I was drunk. Here we go:

General Platonism is the belief that there exist transcendent truths. That's it. Nothing more here. One of these truths is “(ZFC) ⇒ (1+2=3)”. I won't even comment on whether or not ZFC is true.

So, to conclude, General Platonism is a belief, yes, but it cannot be considered a religion.