With regard to the Gospels that the Christians have, there are four Gospels, Matthew, Mark, Luke and John. They are agreed that Luke and Mark did not see the Messiah, rather he was seen by Matthew and John.
These four accounts which they call the Gospel, and they call each one of them a Gospel, were written by these men after the Messiah had been taken up into heaven. They did not say that they are the word of God or that the Messiah conveyed them from God, rather they narrated some of the words of the Messiah and some of his deeds and miracles. End quote.
Moreover, these books which were written after the time of the Messiah did not remain in their original form. The original versions were lost long ago. Ibn Hazm said:
With regard to the Christians, there is no dispute among them or anyone else that only one hundred and twenty men believed in the Messiah during his lifetime… and all of those who believed in him concealed themselves and were afraid during his lifetime and afterwards; they called people to his religion in secret and none of them disclosed himself or practised his religion openly, because any of them who was caught was executed.
They continued in this manner, not showing themselves at all, and they had no place where they were safe for three hundred years after the Messiah was taken up into heaven.
During this time, the Gospel that had been revealed from Allaah disappeared, apart from a few verses which Allaah preserved as proof against them and as a rebuke to them, as we have mentioned. Then when the Emperor Constantine became a Christian, then the Christians prevailed and started to practise their religion openly and assemble in safety.
If a religion is like this, with its followers practicing it in secret and living in constant fear of the sword,
it is impossible for things to be transmitted soundly via a continuous chain of narrators and its followers cannot protect it or prevent it from being distorted.