It is reported that ʿAbdullāh b. Al-Mubārak – Allāh have mercy on him – said:

The insightful and wise do not trust that they are safe from four things: a past sin about which it is not known what the Lord Almighty will do, the remaining lifespan wherein it is not known what destruction lies, some (apparent) advantage a person is given but which could be a lure (from Allāh) in recompense for his wrongdoing, a misguidance that has been beautified – so that he thinks it is guidance – and a momentary deviation of the heart, for a person can be stripped of his religion without realizing it.

Al-Dhahabī, Siyar Aʿlām Al-Nubalāʾ 8:406.