Exactly.
12 men did not go out into the world to convert people to a Lie. Nobody risks their life for an idea that they know is a lie.
That's the real Proof that there was a Resurrection (and that He existed).
Let the Muslims prove that Mohammed existed. So far as I know, the only sources we have are Muslim in origin. But the opinion that the Christian Scriptures are unreliable has nothing to do with the well establishmed fact that they are documents from the period. What evidence does the gentleman have to prove that their testimony is false?