"Fear being the root cause of what we can see as mental illness." ?????
Well, you have a right to your own opinion.
God gives us a spirit of power, love, and a sound mind as the bible states?
Hallelujah! I am happy to have been cured of my mental illness by just being a Christian. Jokingly, of course.
God has given me a sound mind (well, may be, a sort of a sound mind) through the availability of medications, yes.
Although I am truly happy for you that you believe God has helped you with your so-called bipolar condition, I would be cautious about stating that by faith in God alone cured you of your illness even though it may be true for you, since many others are NOT as BLESSED and may think that God alone will cure them also.
Back to the original post, my parents are not Christian. They have been married over 50 years. They are still going strong. Their marriage did not help me though since I am divorced. I have a mental illness that at times impairs my judgment, and I married too hastily with repercussions that led to my divorce. My ex-husband a non-believer wanted the divorce after I ran away from him. He started the proceedings, not I. If I had followed my parents' model of marriage, I would have never married my ex. At least, my parents share the same culture, language, and values, whereas my ex and I did not. My parents are a good couple even though they are not Christian. They care for each other in a way that is not as obvious by their statements, but through their interactions with each other and what they do for each other. I wish I could have had a marriage like my parents. But, I am happy with what I have now and am not expecting to marry again.