The gospels usually refer to the first four books of the New Testament: the Gospel of Matthew, Mark, Luke, and John. They are the primary books of the Bible that narrate the life of Jesus. They are also the closest thing we have to good historical sources about Jesus. Each gospel has a different emphasis and content. The three most similar gospels are referred to as the synoptic gospels, comprising Matthew, Mark and Luke.
Various other apocryphal gospels exist but were not selected for inclusion in the Bible. Though the historical value of the canonical Gospels is highly debatable, scholars judge that the non-canonical gospels are even less likely to be historical.
Since the 2nd century, Christians have claimed that the gospels were written by Jesus' disciples and their companions. However, Bible scholars generally consider the gospels to be the work of anonymous authors. Based on the text, the authors seem to be Greek-speaking, educated, rhetorically-trained writers who were skilled in Greek composition (but who never called themselves disciples) - they were not written by uneducated, illiterate, lower-class, Aramaic-speaking, disciple peasants who never went to school and who possessed no knowledge of literature. This fact is accepted even by very conservative scholars such as Craig Blomberg.  The names of the gospels were only added after they were written.
The titles gospel manuscripts we have say things like "according to Matthew" rather than "by Matthew", which indicates their indirect nature. Another reason for this conclusion is that they are shared content rather than being independent accounts, and they contain factual errors and discrepancies between manuscripts.
As eyewitness accounts
- Main Article: The Bible was written by eyewitnesses
Attempts by modern apologists to defend the eyewitness status of the gospels often betray an ignorance of basic Biblical scholarship. The synoptic gospels share almost identical stories indicating they were based on the same source text or each other. This would not be necessary if they were independent eye witnesses. Because of the time between the events they describe and when they were written, almost all eyewitnesses would have died but it is not impossible for rare individuals to live to old age.
Reuse of text
TODO Amount of shared content and the Q source.
Many parts of the gospels were added after their first version, such as the end of Mark 16 , and the story of Jesus saying "let he without sin cast the first stone." John 8:1-11 There is a whole list of pieces that were later added in,  and many of the books in the NT written by forgers  (all this done by early Christians). Since the gospels have been deliberately meddled with, mistranslated many times, and changed over centuries of oral traditions, there is no sound basis for trusting them as reliable historical documents.
Mainstream scholars conjecture that the gospels were written sometime between 66 A.D. and 110 A.D., with Mark being written first and John being written last. Conservatives argue that Luke/Acts must have been written before Paul's death c. 64 A.D. because it does not mention the event. This would imply that Mark was written even earlier, because Luke appears to have copied from Mark. However, it seems Luke/Acts was designed to pitch Christianity to Gentiles, and if this were the case it would make sense to end with Paul's declaration that Jesus came to save Gentiles rather than the unfortunate fact of Paul's death at gentile hands.
Even if the first gospels were written in the late 50's or early 60's, we would still have a gap of about three decades between the events recorded and their composition. Apologists regularly claim that even by mainstream dating, the gospels were written too early to contain any legendary components. However, numerous counter examples to this claim can be given. However, many legends form soon after the original events, including Sabat Sevi, Charles Manson,, John Frum cargo cults and the Roswell UFO incident.
- Gospel of Matthew: Jesus as the promised Messiah and is Son of God. The audience was intended to be Jewish and Jesus was sent only to the Jews Matthew 15:24 .
- Gospel of Mark: a biography of Jesus for gentiles, including the Romans. Jesus is a miracle worker, prophet and suffering servant of God.
- Gospel of Luke: intended for a Greek or gentile audience. Jesus is presented as more compassionate for outcasts and as a "perfect example of humanity".
- Gospel of John: intended for Christian audience. It links Jesus with eternal life and more directly establishes his divinity. John is the most distinctive of the canonical gospels. It addresses the widening gap between Christianity and Judaism, as well as criticising the Gnostic movement.
Accuracy and truthfulness
- Main Article: The Bible is not a reliable historical source
Mainstream historians consider the gospels to be based on a historical Jesus but were embellish with details and miracles to make them more persuasive. A minority of historians consider the gospels to be fictitious or mythical accounts. Some fundamentalists consider the Gospels to be literally true.
Integrity of the text
- Main Article: Many accurate copies of my holy book exist
A common argument for the reliability of the gospels is that we have many manuscript copies of them. As an argument for the historical reliability of the texts, this is a non-sequitur: making a million copies of a lie will not turn it into a truth. As an argument for the text of the gospels we have today being true to the originals, this argument does have some validity. Our ability to reconstruct the original text of the gospels is much better than for many other ancient documents. However, comparisons of the different gospel manuscripts do reveal discrepancies. Most of these are minor, but there are two places in which large passages seem to be much later additions to the text: Mark 16:8-12 and John 7:53-8:11 . Worse, with the exception of two tiny fragments, all of our gospels manuscripts date from after c. 200 A.D. This means we are in no position to detect any tampering that occurred prior to this date. It should be noted that while this situation is troubling to some believers in Biblical inerrancy, it is not the most serious problem with the historical reliability of the gospels. The problem of legendary embellishment is much larger. Also, contrary to what popular sources such as The Da Vinci Code claim, there is no evidence of large-scale rewriting of the Bible in the era of Constantine.
Because the gospels present four accounts of the same alleged historical events, the opportunity for contradictions on matters of historical detail is arguably greater than anywhere else in the Bible. The opportunity is by no means a missed one. Some of the most serious contradictions:
- John presents a radically different portrait of Jesus than the first three gospels. It is the source of much important Christian theology, but because it was written later than the other three books, scholars judge that it is much less likely to contain historical information.
- Matthew and Luke both trace Jesus' genealogy back to King David, but the two genealogies contradict each other. Likely, both were invented to satisfy the expectation that the Messiah would be descended from David. Christians have made numerous attempts to harmonize these contradictions, but these tend to fly in the face of known facts, i.e. by claiming that one genealogy goes through Mary when both explicitly trace Jesus' descent through Joseph. Modern investigators are fortunate that the authors apparently were not comparing notes.
- Matthew and Luke tell different stories of Jesus' birth. The standard birth narrative presented in movies, Christmas pageants, etc. combines details of both stories without being entirely Biblically accurate. The reason for this is that attempts to harmonize the two stories are implausible at best. Interestingly, both stories serve the purpose of explaining how it came to be that Jesus was born in Bethlehem but grew up in Nazereth. The most likely explanation is that Jesus was born in Nazareth and that the birth narratives were invented in response to the belief that the Messiah would be born in Bethlehem. Again, the authors do not seem to have been comparing notes.
- Different accounts of the dying words of Jesus.
The gospels contain many events that contradict the historical record. 
Because the authors of the gospels are anonymous, it is safe to conclude that the gospels are hearsay. They are not the sort of evidence that would be allowed into a court of law. Though they may contain some historical information, their historical reliability is not well enough established for them to be used to prove Jesus' miracles actually occurred, as some Christian apologists claim. It is likely the actual authors of the gospels were Christians in the early church who invented the idea of the resurrection and divinity of Jesus to suit their agenda of gaining converts. It is likely that this manipulation of the New Testament occurred progressively and begin in the 1st century .
- ↑ Blomberg, Craig. "The Historical Reliability of the New Testament." in Reasonable Faith by William Lane Craig. Crossway Books, 1994. pp. 193-232.
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- ↑ Peter Cresswell, The Invention of Jesus: How the Church Rewrote the New Testament, 2013