Hundreds of denominations and differing interpretations do not prove demonstrably false the idea that the true message of Christ has been present in the world since the time he proclaimed it.
Actually, it does. All of them claim to be “THE One True Faith And All Others Are False.” All of them claim to be the guardians of what you call “the true message of Christ.”
In view of their vast differences of opinion as to exactly what that “true message of Christ” happens to be, it stands to reason that the vast majority of these people are gravely mistaken.
It was the teachings of Jesus, who claimed to be the the Jewish Messiah, that eventually sent the message of salvation from sin and reconciliation with God to all nations.
No it was not. It was the deciples and then predominantly Paul…who is the inventor of the faith as we understand it for the most part…who sent some sort of message out. Whether or not any part of came from Yeshua Bar Yosef…if the man even existed in the first place….is something we will never know because Yeshua never left anything in writing by his own hand to check against the claims made on his behalf.
And please be aware that there were all kinds of different sects with vastly different ideas about what this “True Message Of Christ” was, the Gnostics being the most prominent among them and known to us only because their writings survived. The rest ended up on a bonfire somewhere and what little we know about them comes from hostile witnesses.