Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. – Matthew 5:17
Matthew is one of the three Synopic Gospels (along with Mark and Luke because they all three contain similar stories, similar wording, and are in a similar sequence.)
It was written in Greek between 80 a.d. and 90 a.d. (The Council of Jerusalem happened in year 50 a.d. and the destruction of the Temple in Jerusalem happened in the year 70 a.d.)
Because the Book of Mark was likely used as a source, it had to be written after Mark was (which was in 66 a.d. to 70 a.d.) – which explains it’s similarity. Since the author doesn’t bother to explain Jewish customs, then his intended audience was likely Jewish and understood them.
As with all genealogy lists referring to Jesus, the idea has been to establish him as a descendant of King David and therefore the one meant to fulfil the prophecy of an enduring kingdom. We might not know how Mary and Joseph were related – but in a very small community of big extended families, some degree of intermarriage was traditional and common.
One focus of Matthew’s gospel is the emphasis that the law was not destroyed, but fulfilled by Jesus’ actions. In a church that was becoming increasingly Gentile, these Jewish believers were holding onto their traditions of keeping the law. It was the idea that these Jewish believers didn’t have to stop being Jews to be Christians, too. Matthew referred over and over again to the Old Testament, showing how Jesus had come to fulfil the prophecies.
20% of the text is unique to Matthew
10% of the text is shared between Mark and Matthew
25% of the text is shared between Luke and Matthew
45% of the text is shared with Matthew, Luke, and Mark
Matthew is the first gospel because at the time the cannon was being debated, it was believed to have been the first one written, and that Mark was a review of Matthew, though now there seems to be enough evidence to indicate that the reality was the other way around.
“In an attempt to unify the church he declared Mark, Matthew, Luke, and John the only Gospels that Christians should read. For Irenaeus the number four was extremely important: there were four directions, four winds, and he reasoned that there should be four separate gospels as well.” – http://www.nationalgeographic.com/lostgospel/timeline_04.html
37 Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ 38 This is the first and greatest commandment. 39 And the second is like it: ‘Love your neighbor as yourself.’ 40 All the Law and the Prophets hang on these two commandments.” – Matthew 22:37-40