Allah (swt) said (which means) :
The hypocrites men and women, are from one onother: they enjoin evil and forbid good. [at-Taubah (9) : 128]
The believers, men and women, are awliyyaa’ (helpers, supporters, friends, protectors) of one another: they enjoin good and forbid evil. [at-Taubah (9) : 67]
In these verses, Allah (swt) has made the enjoining of good and forbidding of evil a characteristic with which to differentiate between the believers and the hypocrites. He makes it clear that forbidding evil and enjoining good is a trait to the believers. Indeed, it is a characteristic of our Prophet Muhammad (saw) which the Qur’an mentions thus:
He enjoins good upon them and forbids them from evil.[at-Taubah (9) : 71]
It is also a characteristic of this Ummah and a precondition for its virtue and success:
You are the best of peoples ever raised for mankind; you enjoin what is right and forbid what is wrong, and you believe in Allah. [al-A’raf (7) : 157]
Mujahid said:
Being the best of all peoples is conditional in the characteristics mentioned in the verse.
 Al-Qurtubi said:
You are the best of peoples only if you enjoin good and forbid evil.
 Therefore, this compliment of our Ummah depends on whether we enjoy these two characteristics. If we do not, we will no longer be worthy of this praise. Indeed, we will deserve chastisement and be doomed for destruction.
 Imam an-Nawawee said:
You should know that this issue, the enjoining good and forbidding evil, has mostly been neglected over a long period of time. What remains of it today is but a few traces, all despite the fact that it is an important issue which lies at the heart of all affairs.