Definition of Synoptic Gospels
He refers to the writings of Lucas, Mateo and Marcos, on the idea that there is a connection between the three visions, a consequence of data and crossed stories that can be seen from making a comparison. It is in this sense that the term synoptic is used.
Approach to the synoptic "problem"
In the New Testament the first three books are the gospel according to Matthew, according to Mark and according to Luke. They are called synoptics because all of them maintain the same structure and very similar content.
According to experts in biblical subjects this coincidence is not accidental and for this reason it is believed that all three testimonies must come from the same literary text or from a common source. At this point we talk about the synoptic problem to refer to what could be the common element from which the gospels of Matthew, Mark and Luke emanated.
From theology, there is no synoptic problem because the three gospels come from the word relieved by God. However, there is a "literary" problem: determining which text or oral source contains the original information of these gospels.
According to the criteria of G. E Lessing the three evangelists were based on a Gospel written in Aramaic that finally disappeared.
A second hypothesis , defended by H. Koester, argues that before Mark there was another evangelist with the same name and his work served as a reference for Matthew, Luke and the Mark we know.
The third option is defended by J. J Griesbach and according to it the first gospel was that of Saint Matthew, which served as the basis for the narration of Saint Luke and Saint Mark (this conception is based on data collected in the New Testament : Matthew was a direct disciple of Jesus of Nazareth).
According to the last explanatory hypothesis, supported by the Protestant theologian Christian Wiesse and accepted by most researchers, there were two original sources: the testimony of Matthew and Luke. Both gospels would share a common source, which the researcher called it with the letter Q (Q in this case is the abbreviation of the word Quelle in German, which means source).
Hypothesis Q, also known as Gospel Q or Source Q, refers to the common material of the evangelists Matthew and Luke but excluding Mark. According to this conception the content of the synoptic gospels would be related to the oral tradition of the first Christians.
Canonical Gospels and Apocryphal Gospels
The so-called canonical gospels are those that have been officially recognized by the Catholic Church (the three synoptics already mentioned plus the Gospel of John). All these testimonies refer to the direct or indirect contact that the apostles maintained with Jesus of Nazareth.
The apocryphal gospels are those that did not have the official recognition of the Catholic church and were written after the canonical ones.
Apart from their official recognition within the Catholic canon, these texts attempt to provide information on aspects of the life of Jesus of Nazareth that do not appear in the canonical texts.