Even if you don't want to actually join them, what about simply voting for them? They won't take your religious freedom away, I can pretty much guarantee that.
It's hard to argue your point in light of how darn frustrating things are right now and how much the CP has got it right on the issues. But for me, the way the matter is stated there makes it impossible for me, as a matter of conscience to vote for them. I have no quarrel with people with those particular beliefs, but a vote for a party with that preamble is too close to an endorsement of a statement which is contrary to my most deeply held principles of faith.