There exists vast differences. They can be enumerated as follows:
1. Although the Bible does indicate that Jesus preached 'the Gospel' (Mark 1:14, 15, 8:35, 14:9, 10:29, Mathew 4:23), there is no evidence, whatsoever, to the effect that 'the Gospel' was written down in any form during his own time. As for the Qur'an, it was recorded during the time of Muhammed (e) itself, and that too, in numerous scrolls.
2. 'The Gospel' which Jesus had preached was not memorized, verse by verse, by any amongst his contemporaries. There were, however, hundreds of followers who had memorized the entire Qur'an by heart.
3. It was not the Gospel preached by Jesus that was written down by Mathew, Mark, Luke or John. Theirs was but an account of all that they had come to know of the life of Jesus (Luke 1:1-4). The Qur'an, on the other hand, is not the biography of Muhammad (e); it is the revealed scripture that was provided to him by the Lord Creator.
4. The compilation of the Qur'an had taken place with a rigour and diligence which the Caliph, as the representative of the people, had commanded. Just how strict the standards of compilation were is to be clearly seen in the words of Zaid bin Thabit who had been entrusted with the duty : 'It would have been easier for me if Abu Bakr had asked me to move a mountain from its place.' As for the Gospels, they are but books that have been written according to the whims and fancies of each writer. As for their objective, it was but to introduce the figure of Jesus to the society in which they lived. (Raymond E. Brown, Responses to 101 Questions on the Bible, Page 57-58)
5. The Gospel came to be written at least five decades after Jesus. The compilation of the Qur'an, on the other hand, was initiated in the twelfth year of the Hijra - two years after the death of the Prophet.
6. It was not the disciples of Jesus who wrote the Gospels. But it was the disciples of Muhammad (e) who had compiled the Qur'an.
7. The Gospels were based only on the hearsay accounts about Jesus. On the other hand, the compilation of the Qur'an was based on the scrolls which were written the under instruction and supervision of the Prophet and on the versions of hundreds of followers who had directly heard and memorized the Qur'an from the Prophet himself.