Religious ideation is one of the primary symptoms of the mentally ill. Some cases are more acute than others.
The book, “Rethinking Maddness” gives a new perspective on mental illness, especially schizophrenia. In that perspective, mentally ill people subconsciously tear down their personal realities because their lives have become unbearable.
Yes, it is likely that those people will become religious or spirituality oriented, and subsequently will have a full recovery, recovery in that they will begin to function and care for themselves. They report finding new value and meaning in their lives.
Their chances are much better if they have not been drugged into oblivion in the interim.