The four evangelists are the putative authors behind the Gospels, the sections of the New Testament which deal with the life and works of Christ. These Gospels were written anonymously around the time of Christ, with Christians later ascribing their authorship to Matthew the Evangelist, Mark the Evangelist, Luke the Evangelist, and John the Evangelist. These four men are known as “evangelists” because they spread the word of Christianity to the world through their works and the Gospels, referencing the Greek word for “spreader of good tidings”.
Matthew the Evangelist is believed to have been one of the 12 Apostles linked with Jesus Christ, and he is recognized as a Saint, as are the other evangelists. In Christian iconography, Matthew is often represented as a winged man, which some people mistakenly believe is an angel. The winged man represents humanity and reason. John the Evangelist was also an apostle, traditionally represented by the figure of an eagle, referencing the complex theology which appears in the Gospel of John.
Mark and Luke are known as “apostolic men,” meaning that they followed apostles of Christ. Mark is traditionally represented by a winged lion for courage, while Luke is represented with a winged ox, who represents strength, service, and sacrifice. The four creatures associated with the four evangelists often appear together in the form of a tetramorph, an arrangement of the creatures which is divided into quarters by a cross.
The iconography of the four evangelists is quite interesting, and also very complex. In addition to representing the evangelists themselves, the animal figures also represent Christian virtues, the traits which should appear in all devout Christians, as well as referencing the nature of Christ Himself. In addition, they reference the “living creatures” featured in the Book of Ezekiel.
For Christians, the four evangelists are obviously important figures because they helped to spread Christianity. They often appear in works of Christian art, often accompanied by the animal figures which represent them, and in some Christian communities, celebrations are held on their Saint's Days to recognize their contributions to Christian faith.
Naturally, there is some dispute as to the true identity of the authors of the Gospels, and whether the four evangelists are the people they are believed to be. It is possible that the Gospels were written by other people, or by a collective.