The gravity of sins underestimated by their doers
Nahj al-Balāgha|Volume 1|Book 3|Chapter 348
٣٤٨. وَقَالَ (عليه السلام): أَشدُّ الذُّنُوبِ مَا اسْتَهَانَ بِهِ صَاحِبُهُ.
348. Amīr al-mu’minīn, peace be upon him, said: The most serious sin is that which the doer considers light. [1]