Islam started with the onset of creation, not with prophet Muhammad (PBUH), as is reported in some of the Western literature. When Allah created the heavens and the Earth, Allah asked, “Do you come in submission or do you come in disobedience?” They said, “We come in submission!”
Allah created the universe and created the moral codes and physical codes and created Adam and from the same material He created Adam’s wife. We are the offsprings of Adam and his wife. And when the people multiplied on the Earth, Allah chose form the middle of the class a person to convey the full moral codes and physical codes that was sent to every nation and every village. Allah said in the last heavenly book, the Holy Quran, there was no nation that Allah did not send someone to warn them, and there was no village that did not receive a messenger. And Allah’s message from the beginning of creation to the day of judgement is applicable in every country and anywhere in the universe.
Allah made it clear from the beginning that to Him religion is Islam. To Allah, religion is to submit to Him. And Allah said in the last heavenly book, the Quran, whoever adopts a religion other than Islam “Submission” it would not be accepted by Him on the day of judgement and that person will be among the losers. All the prophets were Muslims and those who followed them are our brothers in Islam. And the heavenly books are Islamic books: the Torah, the Bible, the books of Moses and Abraham, Pslams of David, and the Holy Quran.
The foundation, the bedrock, the basis of the religion to Allah is to believe in His oneness. The oneness of Allah is mentioned in nearly every chapter of the Holy Quran. Allah gives examples of His oneness. Allah will forgive any human being who will commit a bad deed or sin and repent, but He will not forgive anyone who dies believing in associates to Allah or multiple gods. And Allah said, addressing mankind, “If you associate Me with false gods, then your work on this Earth will not be accepted.” Islam calls for strict monotheism with no deviations. With absolute monotheism Allah said, concerning prophet Muhammad(PBUH), that He is the one who sent His messenger (Prophet Muhammad) with the true religion so it will prevail over all religions that were fabricated by mankind.