After setting out these grave and momentous issues, he entreated Allah for firmness, asking that He not let him go astray together with the people of these deviations and errant doctrines. This, in itself, is true understanding and wisdom: a person must never be duped by his own learning and say, “I already know monotheism and sound creed; no danger threatens me.” That is self-conceit. Rather, he ought to fear an evil end and fear slipping into misguidance, dreading that he might be taken in by the people of error. How many who once stood balanced have later swerved—especially when trials grow intense! A man may greet the morning as a Muslim and reach nightfall a disbeliever, or spend the evening a believer and awake a disbeliever, selling his religion for some paltry share of this world, as the authentic hadith states (1).
When tribulations strike, one should beg Allah for steadfastness (2) and must not say, “I am not…"
(1) Abu Hurayrah, may Allah be pleased with him, reported that the Messenger of Allah, peace and blessings be upon him, said: “Hasten to perform good deeds before trials come like patches of a dark night: a man may rise in the morning a believer and be an unbeliever by evening, or go to bed a believer and wake up an unbeliever, selling his religion for a share of this world.” Recorded by Muslim, no. 118.
(2) Jabir, may Allah be pleased with him, reported: The Messenger of Allah, peace and blessings be upon him, used to say, “O Muqallib al-qulub (Turner of the hearts), keep my heart firm upon Your religion.” We said, “O Messenger of Allah, do you fear for us when we have already believed in what you have brought?” He replied, “Yes, for the hearts are between two fingers of Allah; He turns them as He wills.” Related by al-Tirmidhi, no. 2145; Ibn Majah, no. 3834; and al-Hakim, 1/525–526, 4/321, who declared it authentic, a verdict endorsed by al-Dhahabi. Al-Tirmidhi classed it as hasan (sound).
Muslim also narrates, on the authority of Abdullah ibn Amr ibn al-As, may Allah be pleased with them both, that he heard the Messenger of Allah, peace and blessings be upon him, say: “The hearts of all the children of Adam are between two fingers of al-Rahman (the Most Merciful), as though they were one heart; He directs them as He wills.” The Prophet then said, “O Musarrif al-qulub (Disposer of the hearts), turn our hearts toward Your obedience.” Recorded by Muslim, no. 2654.