First of all, my posts weren't anti religious at all. More political than anything else. The only negative thing I said about the Catholic church is that they have a very stained history, which is simply a fact. Has nothing to do with how you feel about God. And even that only got started because I was trying to give you advice, and happened to quote an atheist.
That aside, we are trying to get you to see that much of the reason you are so upset is because you are making yourself so upset. You know you are going to be disappointed and hurt every time you go through his private correspondences, yet you do it again... Do you see what we're getting at here? You have not detached. You need to work on YOU, not your son. It is his responsibility to work on him. Not only that, the healthier you are physically, mentally, and emotionally; the better help you can provide for him. Codependency is a horrible cycle, and not an easy one to escape. Most of the parents on this forum have made great efforts in the detachment department. Nobody is telling you that it will be easy, just that it will be worth it. It will be more beneficial for you, your son, and the rest of your family.
Just like a junkie needs to forget phone numbers attached to supply sources, you need to remove your ability to read his private correspondences. What you are doing is NOT how you begin to build a healthy relationship with your son when he gets better. SOMEBODY needs to start being honest, and it doesn't look like it will be him. Might as well be you. I promise you, the hard time you're going through will be less hard if you do.