The literary connection can be seen in the Baptism story. Mark has 5 verses, Matthew 15 and Luke 17. And also the Peter Disowns Jesus Mark has 7 verses, Matthew 7 and Luke 9. The fact that these stories are in each gospel suggests some kind of clear connection between them all.
Streeter believed that the order of the gospels was Mark first then Matthew then lastly Luke. He also believed that all the gospels shared a common source which he called Q. This Markan priority theory overtook the Matheau priority in the 19th century. It was suggested that Mark portrayed Jesus to be too human. That mark showed him ‘faults and all’ and when the church was first compiled it was seen to be the case that Matthew was put first as the most important gospel with the most verses and therefore as they saw it; the most historical content. It is believed that as Mark is the priority gospel and that Matthew and Luke took Marks account and then expanded on it to write their own. It is also true that using this theory the Matthew and Luke have taken Marks gospel and tidied it up by correcting his poor Greek. It is known that mark used long narratives and in Matthew and Luke it can be seen that these have been abbreviated. Mark is also seen as the priority gospel as it appears to give an all rounded approach to the life of Jesus. Where as, Mark and Luke give a more soften approach where Jesus is seen as truly perfect light whereas in Mark critical observations are given about him. This suggests that just like in life a true account gives the good and the bad. And finally it is also true when looking at the reason for Markan priority that had Mark not been the definitive gospel there would be no point keeping the shorter gospel in the cannon of the bible.
I think that the Markan priority theory is a good theory due to its large amount of substantial points. For example looking at real life I know that a true account gives the good with the bad. This can be seen if you read some ones diary. When talking about friends you do not only write the good. You write the bad also because you just write as you see it, with no bias. This suggests that Marks gospel is the truer and therefore oldest account.
Holtzman’s two source theory states that Matthew and Luke used Mark as well as another common source; he called this source Q. He believed that Q comprised of 230 verses which were true sayings of Jesus.
Source Q provides us with evidence for the similarities that occur between Luke and Matthew that Mark cannot account for.
Some people believe that it could be argued that Luke did not use the Q source but instead compiled his gospel from that of Matthews. However if this is the case then during the compiling of the bible there would be no point including all three gospels as if they just used Luke it would therefore be a compilation of the other two gospels and could stand alone as a definitive document on its own. Either this or they would of only included Mark and Matthew as Luke would only be a summary of what has already been said. It can be said that all three gospels must have been kept as they each have some significance and individual interpretation in certain particular areas.
I believe that the arguments in favour of the use of the Q source are the most conclusive. This is because I believe that there is the most evidence for this cause. For example there are many points that point towards the combined use of Mark and Q between Luke and Matthew.
However, it is hard to understand exactly what the truth is behind the question of the synoptic gospels. Evidence of this can be taken from the discovery of the Dead Sea scrolls. The information provided from these and the Jesus papyrus suggest that there were/are many documents that all the gospel writers could take their information from and suggest that much of the information in the gospels was taken from writings not only from common oral traditions. I believe that it would be hard now to ever understand fully what exactly all the gospels information was taken from and as time slips by so does evidence.
The reasons for looking at the synoptic problem are that of trying to help aid us in our understanding of the gospels themselves. As by studying which came first we can then understand where the truth lies and where bias can be placed.