Mostly, yes. Religion/faith was created to keep people docile and obedient. It's a control mechanism. Also it keeps human beings hopeful that if they behave themselves while alive, they'll go to some place where their souls will live forever when they die. Dogma and propaganda are very powerful things.
World wars, millions killed, plagues, diseases, young children dying of cancer and other horrible things? There is NO god.
How does anything you just said make faith in God a mental illness?
Is this guy mentally ill, for example?
Francis Sellers Collins (born April 14, 1950) is an American physician-geneticist who discovered the genes associated with a number of diseases and led the Human Genome Project. He is director of the National Institutes of Health (NIH) in Bethesda, Maryland, United States.
By graduate school Collins considered himself an atheist. However, a conversation with a hospital patient led him to question his lack of religious views, and he investigated various faiths. He familiarized himself with the evidence for and against God in cosmology, and on the recommendation of a Methodist minister used Mere Christianity by C. S. Lewis as a foundation to develop his religious views. He eventually came to a conclusion and became a Christian after a "leap of faith" when he saw a frozen waterfall during a hike on a fall afternoon. He has described himself as a "serious Christian".
https://en.wikipedia.org/wiki/Francis_Collins#Christianity