As we've seen in recent posts, the text of the New Testament is on much firmer ground than the text of the Qur'an. While Christians in the third century had temporary disagreements on minor books of the New Testament (e.g. 3 John), we find disagreements among Muhammad's closest followers as to which books should be included in the Qur'an. Moreover, we find that individual verses, sections of Surahs, and entire Surahs are missing from the Qur'an. Beyond this, when Christians are confronted with textual variants, we are able to investigate these variants using the principles of textual criticism, along with our manuscript tradition. Muslims, on the other hand, systematically destroyed their manuscript tradition, which means that textual critics can't investigate the significant variants at all. Further, as Nabeel pointed out, universal corruption of the Qur'an was possible, since all copies of the Qur'an were at one point in the hands of Uthman. That is, at one point in Islamic history, a human being had the power to make changes in all future editions of the Qur'an. Universal corruption was never possible in Christianity, however, since no Christian ever had all manuscripts of the New Testament.
Thus, Muslims who claim that the textual transmission of the New Testament is somehow inferior to that of the Qur'an simply don't know what they're talking about. Nevertheless, there is an even more important point here, which Nabeel alluded to in his last post. Textual variants don't have the same implications in Christianity as they do in Islam. Allow me to explain.
The core of the Christian message is the Gospel of Jesus Christ. The Gospel is primarily a message about Jesus' death, resurrection, and deity. Notice, however, that all three of these issues are a matter of historical investigation. Jesus' death by crucifixion was a historical event. His resurrection from the dead was a historical event. His claims to divinity were historical events. The core of Christianity, then, is open to historical investigation. Even more significant is the fact that this core of Christianity is independent of whether the New Testament was perfectly preserved or even inspired. To put the matter differently, Christianity is true if certain historical events occurred. To know that these events occurred, we need reliable records of what happened in the first century. To know that Christianity is true, then, we simply need to know that the New Testament is historically reliable when it reports Jesus' death, resurrection appearances, and claims to deity. While Christians still believe in inspiration, it is important that we recognize that inspiration is not essential to this historical core.
So what's the significance of textual variants in Christianity? These variants are only significant if they cast doubt on Jesus' death, resurrection, and deity. Do any textual variants do this? Not at all. I challenge Muslims to find a manuscript that does not present Jesus as the risen Lord. Our manuscripts are completely consistent on the core of Christianity, and we have numerous early witnesses who testify to the historical core of the Christian message. (Note that our belief does not rest on the word of a single person, as in Islam). We may conclude that textual variants do not affect the truth of Christianity.
Is the situation the same in Islam? Hardly. Muhammad claimed that he received the Qur'an from the angel Gabriel. According to Surah 15:9 (supposedly given to Muhammad by Gabriel), God would perfectly preserve the Qur'an. Do Muslim records of missing verses, missing sections of Surahs, and missing Surahs affect the truth of this claim? Absolutely. Does the fact that Muhammad's most reliable followers couldn't even agree on the correct number of Surahs affect this claim? Absolutely. Does the fact that Aisha's goat ate the Verse of Stoning and the Verse of Suckling affect this claim? Absolutely.
Thus, textual variants falsify Surah 15:9, and this shows that Muhammad did not receive this verse from God. And if Muhammad did not receive this verse from God, why should we believe that he received any of the Qur'an from God? When we add to all of this the fact that Muhammad claimed, on at least one occasion, that he had delivered a revelation from the devil, that his first impression of his revelations was that they were demonic in origin, and that he was admittedly the victim of black magic, do we have a problem here? Undoubtedly.
To show that Christianity is false, Muslims need to show that the core of the Christian Gospel was completely corrupted, and they just can't do this. To show that Islam is false, Christians simply need to show that Allah didn't perfectly preserve the Qur'an, and what could be easier than this? Of course, Muslims will continue, in spite of the evidence, to proclaim that the Qur'an has been perfectly preserved, just as they will continue, in spite of the evidence, to proclaim that Jesus never died on the cross, rose from the dead, or claimed to be divine. But this simply shows that Muslims have very little concern for truth. The facts speak for themselves.