Faith in Allah, the Almighty, is to happiness and peace, while disbelief is to confusion and misery. l have read about many intelligent people of a certain kind, some who might even be called geniuses, geniuses though whose hearts are bereft of the light of guidance. And as such, they spoke wicked words about the Shari’ah (Islamic law). These are two examples that come to mind: Abu al- ‘Ulaa al-Maarri said about the Shariah, "Contradiction, concerning which we can do nothing but stay quiet." Second, is the saying of lbn Seena, "The element that influences nature is the active intellect."
I thus came to know that to the degree that one has faith in his heart will one be happy. More recent sayings, similar in meaning to the two above, are the offspring of the evil words of old that were spoken by Fir’aun:
(Fir’aun [Pharaoh] said: ‘O' chiefs! I know not that you have an ilah [a god] other than me…) (Qur’an 28: 38)
(Fir’aun said: ‘l am your lord, most high.) (Qur’an 79: 24)
James Allen, author of How Man Thinks, said:
"Man will come to know that each time he changes his opinions and thoughts concerning things and other people, those same things and people will in their part also change...
Suppose someone to have changed his thinking, and we will be astonished to learn how quickly the state of his material life changes. Therefore the sacred thing that shapes our goals is our own selves."
Regarding incorrect thinking and its effects, Allah, the Exalted, says:
(Nay but you thought that the Messenger [Muhammad] and the believers would never return to their families; and that seemed fair in your hearts, and you did think an evil thought and you became a useless people going for destruction.? (Qur’an 48: 12)
(And they thought wrongly of Allah --- the thought of ignorance. They said, ‘Have we any part in the affair?’ Say you [O’ Muhammad]:
‘Indeed the affair belongs wholly to Allah.) (Qur’an 3: 154)
James Allen also said:
"Everything that a person accomplishes is a direct result of his personal thinking... And man is capable of triumphing and of achieving his goals through his thinking; he will remain weak and miserable if he refuses to acknowledge this."
Allah, the _Almighty, said of true determination and correct thought:
(And if they had intended to march out, certainly; they would have made some preparation for it, but Allah was averse to their being sent forth, so He made them lag behind…) (Qur’an 9: 46)
(Had Allah known of any good in them, He would indeed have made them listen..) (Qur’an 8: 23)
(He knew what was in their hearts, and He sent down As-Sakinah [calmness and tranquility] upon them, and He rewarded them with a near victory..)
(Qur’an 48: IS)