Has Allah Almighty commanded entry into Islam, and what is the proof of that?

Allah Almighty commanded people to embrace His religion and declared that the only religion acceptable to Him is Islam. Allah Almighty says: "O you who have believed, enter into Islam completely," and "And return [in repentance] to your Lord and submit to Him before the punishment comes upon you; then you will not be helped." Allah does not accept any religion other than Islam from anyone, and whoever seeks a religion other than Islam, he is among the losers. The Prophet Muhammad, peace and blessings be upon him, was sent to all mankind with guidance and the religion of truth to make it prevail over all other religions. The evidence for this is abundant in the Qur'an and Sunnah (definition).