Matthew, of course, was a tax collector called by Christ to be one of his Apostles. Matthew is also one of the four Evangelists and is the patron of bankers and accountants.
Here is today's Gospel reading for Mass:
As Jesus passed by, he saw a man named Matthew sitting at the customs post. He said to him, “Follow me.”And he got up and followed him. While he was at table in his house, many tax collectors and sinners came and sat with Jesus and his disciples. The Pharisees saw this and said to his disciples, “Why does your teacher eat with tax collectors and sinners?” He heard this and said, “Those who are well do not need a physician, but the sick do. Go and learn the meaning of the words, I desire mercy, not sacrifice. I did not come to call the righteous but sinners.”
Here is a very well known Caravaggio entitled the calling of St. Matthew. If you're not already familiar with this series of videos produced by SmartHistory and the Khan Academy, they are well worth exploring through the Khan Academy. Here is the link to their Renaissance videos.
The above painting is located in San Luigi dei Francesi in Rome along with two other paintings by Caravaggio regarding St. Matthew: (1) The Inspiration of St. Matthew and (2) The Martyrdom of St. Matthew. Both are below.