Who was Saint Matthew, according Benedict XVI
“Matthew, the author of the first of the four Gospels, was a publican – a tax-collector – and the story of his call to become an Apostle reminds us that Christ excludes no one from his friendship.
Tax-collectors were considered public sinners, and we can hear an echo of the scandal caused by the Lord’s decision to associate with such men in his declaration that he came "not to call the just but sinners" (Mt 2:17).
This is the heart of the "good news" which Jesus came to bring: the offer of God’s grace to sinners! The parable of the publican in the Temple makes this same point: by humbly acknowledging their sins and accepting God’s mercy, even those who seem farthest from holiness can become first in the Kingdom of Heaven.”