Since you asked I will answer...but since you asked you WILL HAVE TO LISTEN...Ask again if you dont understand!
Like all religions, Islam doesnt believe it was born at a particular time...It has been the religion of the planet since before time coz Islam literally means one who bows to god's will...
The worshiping 1 god has always been the msg of ANY msgr! We believe in all....it is the fundamental belief without it you cant be Muslim...We have 6 articles of faith..Go against even one makes you no longer a Muslim:
Believe in the
Oneness of God - the shahadah is the entry ticket and the article is re-establishing it!
Messengers and Prophets of God - We have no exact number..Jewish sources tell us there were over 14k (hence why we believe that any book/ scripture talking about 1 god was indeed from 1 of the many prophets and the religion got adulterated later on)....but only 25 are named in the Quran so we cant reject a single one!
There is a verse in the Quran which says for EVERY NATION and age we sent a msgr as a warning...
Holy books - 4 are mentioned by name: Zabur (Daud/ David), Torah (Musa/ Moses), Injeel (Isa/ Jesus) and Quran (Muhammad) but some are called SUHUF given to other prophets...Each was for their tribe and their time except Quran which is complete for everyone and until day of judgement...
Angels - We believe in them and that they are made of light and some have been used as msgrs to pass the msg from GOD to his chosen human (prophet)
Day of judgement - that there will be a day where it all ends and our good and bad deed will be judged before our GOD the just!
Predestination - where we believe GOD knows everything that is going to happen coz HE is god ABOVE all...the MOST knowledgeable! Why somethings are done (silver linings) are either to teach us to be stronger (harm, diseases), stopping a larger calamity from hitting us (a girl/ boy leaving us, getting lower grades than we expected), knows whats best for us (why we got so and so as a spouse over our choice) and so on...
Now those who believed in the books and the prophets during their time were Muslims...as everything comes from the same 1 god...