Muhammad's mission involves preaching monotheism. The Qur'an demands Muhammad to proclaim and praise the name of his Lord and instructs him not to worship idols or associate other deities with God but to only worship the one God.According to the Qur'an, one of the main roles of Muhammad is to warn the unbelievers of their eschatological punishment (Qur'an 38:70, Qur'an 6:19). Sometimes the Qur'an does not explicitly refer to the Judgement Day but also provides examples from the history of some extinct communities and warns Muhammad's contemporaries of similar calamities (Qur'an 41:13)