The believers, men and women, are Auliyâ' (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) AlM a' rûf (i.e. Islâmic Monotheism and all that Islâm orders one to do), and forbid (people) from AlMunkar (i.e. polytheism and disbelief of all kinds, and all that Islâm has forbidden); they perform AsSalât (IqâmatasSalât), and give the Zakât, and obey Allâh and His Messenger. Allâh will have His Mercy on them. Surely Allâh is AllMighty, AllWise.
If the people see an evil and do not change it, soon Allah will punish them all.
Whoever, among you, sees something abominable should rectify it with his hand; and if he has not strength enough to do it, then he should do it with his tongue; and if he has not strength enough to do it, (even) then he should (abhor it) from his heart, and that is the least of Faith.
Then, Allah (Glorified be He) says: they perform AsSalât (IqâmatasSalât) and give the Zakât Thus, Mu'mins establish Salahs and observe performing them at their due times, where the men should establish them at the Masjid in congregation with their brothers.
the Prophet (peace be upon him) said: That which differentiates us from the disbelievers and hypocrites is our performance of Salah. He who abandons it, becomes a Kafir.