He is Isa bin Maryam just like Holy Prophet (saw) prophesised. In religious world prophecies are never meant literally and are always metaphorically described, otherwise there will be no value of eeman (faith) if everything is written in black and white. Look at the entire history of religion. The name of the Holy Prophet (saw) is written in bible but not exactly like Muhammad but in meaning. Even the Holy Quran calls him Ahmad but his name is Muhammad (saw):
And call to mind when Jesus, son of Mary, said, ‘O children of Israel, surely, I am Allah’s Messenger unto you, fulfilling that which is before me of the prophecies of the Torah, and giving glad tidings of a Messenger who will come after me, his name being Ahmad. And when he came to them with clear proofs, they said, this is manifest sorcery.’ (61:6/7)
See Holy Quran even witnesses to the fact that even with clear proofs people called it manifest sorcery. Even the arrival of Messiah in Jews had metaphorical prophecies. This is why Jews are still waiting for their Messiah because they want those prophecies to be literally fulfilled. They also take things literally and waiting for Elijah to come down from the sky, whereas Isa bin Maryam himself told them that John the Baptist is Elijah and no one will come down from the sky like they are expecting. This is the answer he gave them, how can one expect now that he himself would do the same which he rejected?
When Holy Prophet (saw) was asked that he should go to the sky and bring a book, he said but I’m a human being and a prophet (Holy Quran 17:92/93) why he gave that answer? Because a prophet of Allah is a human being and he cannot go bodily to the sky. Otherwise this answer will not make any sense.
You should think on this a bit more why Messiah and Mahdi was to come? Holy Prophet (saw) said a lot of things about the time when he was/is to come. One of his prime objectives is to bring the Muslims back to true Islam. Holy Prophet (saw) prophesised that Muslims and their scholars would have gone astray. Lots of Ahadith on this subject that can be provided later. So if scholars were corrupt and Muslims following them would be corrupt, would there not be a problem in recognizing the true Messiah and Mahdi? Of course. That is why many learned scholars of Islam predicted centuries ago that Messiah and Mahdi will face severe persecution from the Ulema and will be called Kaffir that is destroying their religion. References available.