My existential crisis came from my "stability" being built on an eggshell foundation. I had given God credit for saving my life from a bullet and dragging me out of my lifestyle choices to "The Truth."
When that turned out to be a lie, my foundation (built upon for nearly 2 decades) simply collapsed.
Starting over again, I got through the stages of grief at losing the God I thought I knew. I finally figured out that it is I (myself) that saved my life. I chose to live and the fairytale God was my security blanket until I could let go of it and be a mature person who looks at things sceptically.
The actual deep truth, based on facts and reality, doesn't care what anyone believes or change based on false beliefs. There is much to ponder and learn and one can find a comfort from true knowledge and science that is way better than the fairytales and security blanket. It is a pearl for the finding when you are ready.