{ And among the people there are those who sell themselves seeking after the good pleasures of Allah; and Allah is compassionate to the servants. Oh you who have believed! Enter completely into peace and do not follow the steps of Satan; indeed he is a clear enemy to you } Al-baqara 207-208

This was when Allah the Exalted made it clear to people – Believers, Disbelievers, and hypocrites; He said: Be of one religion, come together in Islam, and abide by it. “Peace” [silm] here means Islam; Mujahid said this and Abu Malik related it from Ibn ‘Abbas.