?O people! Ask Allah for conviction and seek good health from him, for the greatest of blessings is good health and the best thing that can reside in the heart is conviction. A cheated man is he who has been cheated of his religion and an enviable person is he whose conviction is envied.'
Imam Ali ibn Abi Talib [as]
Bihar al-Anwar, v. 70, p. 176, no. 33