One of the foremost experts in psychology of our time, Dr. Carl Jung, mentioned on page 264 of his book The Modern Man In Search Of Spirit:
"Over the last thirty years, people from all over the world have come to me seeking advice. I treated hundreds of patients and most of them were middle-aged, or more than thirty-five years old. The problem with every one of them returned to one issue - seeking refuge in religion, and by doing so, being able to have a perspective or outlook on life. I can reasonably say that every one of them became sick because they missed out on that which religion has to offer to the believer. And the one who does not develop a true faith cannot be healed."
(But whosoever turns away from My Reminder [i. e. neither believes in this Qur’an nor acts on its orders, etc.] verily for him is a life of hardship...)
(Qur’an 20: 124)
(We shall cast terror into the hearts of those who disbelieve, because they joined others in worship with Allah...) (Qur’an 3: 151)
(Darkness, one above another if a man stretches out his hand, he can hardly see it! And he for whom Allah has not appointed light, for him there is no light.) (Qur’an 24: 40)