Prophets were sent by God to guide humans. But it is ambiguous and unwise to believe what anyone says.
But what distinguished prophets from others ( for example magicians) was their unchallenged miracles. The miracles were distinct because they were divine and given directly by god ; such that no human things/tricks can defeat it ever. For example, Quran is miraculous because it claims that no book can be written ever guiding (and it's other features.) like it till the day of resurrection.
Hence, one should believe prophets because their miracles are unchallenged by humans; thus making them unambiguous; and hence one of key absolute proofs for submission to god.
One of miracles of Isa(Jesus) (peace be upon him) was to heal people with diseases which were from birth. For example, congenital deafness/blindness. So , does Islam claims that humans will never be able to find cure of congenital deafness/blindness ; thus preserving the un-ambiguity of miracles of it's prophets ?