I know nothing of what induced the therapist to make such a suggestion. However, having read my friend's journal posts, it doesn't seem to me that her religion is causing her any great emotional turmoils at the moment. I could be wrong, of course, but that's my impression.
The only time I would ever make such a suggestion to a patient, if I were a psychological therapist, would be if my patient were clearly in deep emotional distress to the point of contemplating suicide. Then I would have something to say. Presuming my patient's religion was Christianity, though the basic message is applicable to anyone of any faith, my advice would go a bit like this:
"God did not put you on this earth to be miserable. You have a right to happiness just as much as anyone else does. I want you to think about something. There is faith in God, and there is religion. They are two entirely different things. Faith in God is something that exists in your heart. No one has any say in that except God and you. Religion, on the other hand, is an artificial construct. It has priesthoods, and hierarchies, and rules, and writings--all of which were created by human beings, who created these things with all of their opinions and prejudices intact.
"What you need to decide is which of these two is more important to you--your private faith in God, or your adherence to a man-made religion that is causing you much unhappiness--unhappiness that I don't think God ever meant for you to have to feel.
"Sometimes, people regard periods of deep unhappiness as a crucible, as a way to strengthen their faith. But other people are broken by them. I don't want this to break you. God doesn't want this to break you. So think about it. Fairh or religion? Your lifestyle need not be a part of the choice unless you want it to be."
Anyway, as a therapist of the completely unlicensed, armchair variety, that's what I'd advise. It would not be as simple as I've put it, of course. People who are deeply distressed are often not rational, and the message might not get through, despite the therapist's best efforts. But I think this is a heck of a lot better than telling a patient, "I think you should just stop following X religion, and go to something else." I mean, geeze!