‘Abdullāh Ibn al-Mubārak (رحمه الله) said:
The insightful and wise do not trust that they are safe from 4 things:
1) A past sin about which it is not known what the Lord Almighty will do.
2) The remaining lifespan wherein it is not known what destruction lies.
3) Some (apparent) advantage a person is given but which could be a lure (from Allāh) in recompense for his wrongdoing.
4) 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 realising it.
— Mentioned in “Siyar A’lām an-Nubalā’” (8/406).