The ignorant (or malicious) often claim that the Bible has been altered/corrupted over time, or that the canon selected at the Council of Nicaea was not representative of scriptures in common use and circulation in the churches. And those who are uneducated on the matter always fall for it.

But in fact the fidelity of the New Testament texts rests on a vast multitude of evidence, including thousands of complete manuscripts and tens of thousands of fragments, some dating back as early as the first and second centuries. Contrast this with ANY other ancient text to see the vast gulf between them. There is no other ancient text that is better verified than the New Testament.

We know that no substantive changes were made after the fact because copies were already circulating in the early churches -- it was too late at that point to introduce any changes. That is why the book of Acts (a history of the early church) fails to record the death of Paul. It was too late to add new changes by the time of his death in AD 62.

And we know Luke must have been written before that since Acts is a sequel to Luke. And we know Mark must have been written before that since Luke contains a nearly complete copy of the text of Mark. And we know that the pre-Markan passion narrative must have been written before that.

Christ was real, and he was executed for his Messianic claims. Consider the crown of thorns, the reed, the purple cloak, the soldiers bowing down to him mockingly, the "King of the Jews" sign above the cross, the polemic where Pharisees complained to Pilate about the sign, and he replied "What I have written, I have written." Christ claimed to be God and was executed for it. A few weeks later, thousands believed he was risen from the dead and worshiped him as God, in the same city where he was executed. Over the next few centuries the Greeks and Romans entirely discarded their pagan gods, which became mythology, and Western Civilization was born.