Self control

When we read the Quran we may notice that it speaks of some human beings who are higher than angels, but it also mentions some human beings who are inferior to animals. As he says when talking about some negligent people:
They possess hearts but do not feel, have eyes but do not see, have ears but do not hear, like cattle, even worse than them.[1]
So What is the criterion which measures the differences between human beings?

One of the most important criteria for being a righteous believer is self-control. It means that when someone has the opportunity to disobey god and do something wrong, he can dominate himself, his instincts, nerves and passions by his will-power and reason and not be dominated over by his wrong inclinations and desires.

There is a very beautiful narration in this regard. It is narrated that the Prophet was passing by a place in Medina where a number of young men were testing their strength by lifting a heavy stone. When they saw the Prophet, they asked him to act as a judge. The Prophet agreed, and at the end of the competition he said, "Do you know who is the strongest? It is he who controls his anger and does not allow it to overcome him. He must not use his anger in a way contrary to God's satisfaction and should be able to dominate over his own desires."
On that day, the Prophet transformed a physical contest into a spiritual one. What he meant was that physical strength shows manliness but it is not the only sign of it. True manliness strength, is in the strength of will power.

Notes:
[1] هُمْ قُلُوبٌ لَّا يَفْقَهُونَ بِهَا وَلَهُمْ أَعْيُنٌ لَّا يُبْصِرُ‌ونَ بِهَا وَلَهُمْ آذَانٌ لَّا يَسْمَعُونَ بِهَا  أُولَـٰئِكَ كَالْأَنْعَامِ بَلْ هُمْ أَضَلُّ (7:179)
[2] Mostadrak al-Vasaeel. V 9.P 12.