What makes Muslims think the Torah is corrupt?

There is only one God! i mean The God! He is the creator, designer and sustainer of everything! He created Human beings, Aadam ( Adam ) and Hawwa (Eve) being the originals. The originals were brought to planet, called earth, to populate it. God created rules, Dos and Dont's for human beings. God sent prophets and messengers from time to time in order to communicate to human race those Do's and Dont's. Adam being the first prophet. Note: Prophet is different from messenger, Messenger is the one who carries a divine revelation (message) and a prophet is one who propagates the message. So in way, every messenger is a prophet, but every prophet is not a messenger. In all there is mention of 124000 prophets been sent by God in order to guide humanity over time till the time of Prophet Muhammad (pbuh). More detail on this here (Is there any saheeh text about the number of Prophets and Messengers?) Out of all these 124000 prophets, only 4 were given divine messages. —— Torah't (Torah) being the first, revealed to Prophet Mu'sa (Moses) pbuh Zubur (Book of david) being the second, revealed to Prophet Da'wood (David) pbuh Injeel (Bible) being the third, revealed to Prophet Ee'sa ( Jesus ) pbuh Qur'an ( Quran) being the fourth and the last, revealed to Prophet Muhammad pbuh —— The core message of all these divine revelations is the same, "There is only One God!, who is the creator of human beings and everything else that exist and no other!" Apart from the core message, commandments are also given suited to the respective time and era of the messenger. Dos and Dont's, which also are generally the same in all the four revelations (offer prayers, avoid sin, do good, eat this, dont eat that, do this, don't do that, heaven and hell, devil etc) Like a manual. An instruction manual for humanity. Ok Now! Technically speaking, there should only be one manual! why four? That's the question! The answer is two things … 'Time Effect' and ' Human effect' The Time Effect: The core message in all these revelations is Timeless, There is only one God, The God, who is the creator of everything, thats it! No ifs and buts. The Dos and Dont's part … was a 'step by step' process. Somethings that were allowed before, had been forbidden later, "wine" for example, although allowed before, was later totally banned in Quran". No restriction on number of wives before were later restricted to max 4, (conditions apply). In short the rules got stricter but more defined and detailed in general over the time period of these four revelations. Quran being declared the final compilation, and the final 'step' in this long chain of revelations by God himself. The Human Effect: Human effect in short is, 'Chinese whisper', which means that the original revelations due to various 'human' reasons got changed or corrupted, twisted and fabricated to a point that not only the Do and Don't part but also the core message also got lost. So arose the need of a follow up revelation, years and centuries apart in order to.. a) Remind us what original message did the previous revelation contain. b) Point out the errors and deliberate alterations made by humans to the original message. c) Inform us about the updated rules and guidance. In short, Torah came as the first written line of commandments. Before that, there was mostly oral tradition. ( Though, there is mention of Suhuf in some Islamic books, the revelations given to Abraham even before Moses's Torah._ —And it got corrupted over time— Next came Zubur , which pointed out adulterations made by mankind in Torah. (not sure though, I haven't read it ) and carried on to further get in detail of the rules and guidelines. Also discussing time specific issues. —And it got corrupted over time— Next came Bible, which pointed out adulterations made by mankind in Torah and zubur, and carried on to further get in details about the rules and guidelines. Also discussing time specific issues. —And it got corrupted over time— Next came Quran, which pointed out adulterations made by mankind in Torah, and the Bible and carried on to further get in detail of the rules and guidelines, and Finalized them! And God declares that, this is final, there are to be no more changes! Till the day of judgement, all human beings are to follow whats written in this book! Now Quran is considered to be unadulterated and unchanged over time. There is only ONE version of Quran. From Africa to Indonesia, which is word to word similar! So basically, Quran compiles the core message of all the previous three revelations, Torah, zubur and Bible and also holds the latest and final version of commandments, nullifying or overwriting any previous versions of commandments that contradicts with the final version. Issues with Children of Israel, are heavily discussed in the second chapter of Qur'an. It gives clear reasonings and details of what had gone wrong over time with jewish believes and etc etc. If someone is interested in those details, i suggest they read the 2nd chapter Quran, which is Al Baq'ra. Here is a link to my blog, related to the same chapter, might be helpful. Understanding Quran