This would be only true if you could demonstrate either of these two:
1. Humanity does not need any guidance and can just do well on its own: in which case I ask you, why then there are so much corruptions, conflicts wars, injustice...etc?
2. Prove that the Prophets were not really God's prophet. Which off course you cannot, can you?
1) Hinduism, then known as Sanatana Dharma, survived for 2000 years at least before Christ. It survived another 2000 after, and is still thriving. It does really well without prophets. Are you somehow suggesting, that if it weren't for Christ, it would have disappeared? Do you think Hinduism improved after the Islamic invasions destroyed 100 000 temples, killing many innocents on the way. If that was an improvement, I'd hate to know if something bad happened.
2) Who said anything about proving anything. It\s all just belief. None of us can prove anything. It's silly suggesting we can.