St. Matthew, one of the twelve Apostles, is the author of the first Gospel. This has been the constant tradition of the Church and is confirmed by the Gospel itself. He was the son of Alpheus and was called to be an Apostle while sitting in the tax collectors place at Capernaum. Before his conversion he was a publican, i.e., a tax collector by profession.
St. Matthew’s Gospel was written to fill a sorely-felt want for his fellow countrymen, both believers and unbelievers. For the former, it served as a token of his regard and as an encouragement in the trial to come, especially the danger of falling back to Judaism; for the latter, it was designed to convince them that the Messiah had come in the person of Jesus, our Lord, in Whom all the promises of the Messianic Kingdom embracing all people had been fulfilled in a spiritual rather than in a carnal way: “My Kingdom is not of this world.” His Gospel, then, answered the question put by the disciples of St. John the Baptist, “Are You He Who is to come, or shall we look for another?”