The word gospel simply means good news and so therefore the four gospels are the good news of Jesus Christ. Not only do they teach us the teachings and life of Jesus Christ during his ministry, but they are also historically accurate. Those who would endeavour to decry the teachings of Jesus come up against the stone wall of the accuracy of the Biblical accounts which is not surprising when you consider the character of the writers
of the gospels. Matthew and John were both disciples of the Lord Jesus. Mark became a disciple of Peter so that in a sense Mark is Peter’s gospel and, of course Luke was a disciple of the apostle Paul.
Each Gospel tells the same story, often describing the same events in almost the same words. Why, then, are their four accounts of Jesus’ life in the New Testament? The reason is that each of the Gospel writers shapes his account of Christ’s life for a different group of people in the first century Roman Empire. Matthew shaped his account for the Jewish reader, emphasising how Jesus fulfilled the Old Testament’s prophecies about the Messiah. Mark shaped his account for the Romans, to show that Jesus was man of action. Luke shaped his account for the Greeks, to show that Christ was the ideal human being. John’s Gospel emphasises Christ’s deity, and was written to stimulate saving faith in Jesus, the Son of God.
(taken from The Bible: The Smart Guide to the Bible Series by Larry Richards)
While the Gospels are biographical, they are actually thematic portraits of Christ’s life that place very little emphasis on His early life and follow the chronology of His life,
but not slavishly. Not all the Gospels cover the same events in His life. When all four Gospels are put together and “harmonised,” only about fifty days of Jesus’ active ministry are dealt with.
Jesus came in fulfilment of the Old Testament prophesies of a saviour and offers salvation and the true kingdom of God. While some accept Him, most rejected Him, and He was crucified.
(taken from Understanding the Bible in 15 minutes a day by Max Anders)