Hmmm... An all knowing, all seeing, supreme being who condemns you to hell if you don't believe in it. And you're complaining about "demonic" Thais?
You're blaming an increase in depression on a decline in Christianity? Nonsense. I claim Christianity is declining because of an increase in the use of antidepressants. Christianity is depressing.
Western morals exist and maintain their validity in the absence of some crazy deity.
Just because you can't find meaning in life without Christianity, doesn't mean the majority of the rest of us can't.
And lastly, ask any professor of Religious Studies and they will confirm that the overwhelming majority of people who identify with one religion or another, don't participate in religious activities due to faith, they participate due to the support the community provides. If society provides some other form of support and a sense of community, there is no need for religion for most people.