As Jesus was walking along, he saw a man called Matthew sitting at the tax booth; and he said to him, "Follow me." And he got up and followed him. And as he sat at dinner in the house, many tax collectors and sinners came and were sitting with him and his disciples. When the Pharisees saw this, they said to his disciples, "Why does your teacher eat with tax collectors and sinners?" But when he heard this, he said, "Those who are well have no need of a physician, but those who are sick. Go and learn what this means, 'I desire mercy, not sacrifice.' For I have come to call not the righteous but sinners."
St Augustine thinks Matthew wasn’t called at the same time as the others because he had some financial matters to conclude. But a 6th-century writer took it that Matthew left his affairs in disorder, a thing that greatly impressed that writer: it must be particularly difficult for someone who deals with figures to leave them unbalanced. Do we have to balance our books before we set out on the Gospel path?
Matthew wrote his gospel to convince Jews that Jesus was the fulfilment of their prophecies. Sixteen times in his gospel he uses the phrase “so that what had been spoken through the prophets might be fulfilled.” He sees Jesus through the lens of the Old Testament: in him are fulfilled all the hopes of the Jewish people. In view of this conviction, his tax-gathering papers must have seemed very unimportant. Financial matters are so precise, so tangible and near…. His must have been a powerful conversion, because he had been in the service of Mammon, God's greatest rival. “You cannot serve God and Mammon,” he quotes Jesus as saying (Mt 6:24).
Business people tend to be hard-headed, and perhaps his conversion took a little longer. St John Chrysostom suggested that “Matthew was not called at the same time as Peter and John and the others because he was still in a hardened state.” Whatever the case, he was called from his tax business to follow Jesus. It was a call from one way of thinking to another. It was a call from security into insecurity, from wealth to poverty, from power to powerlessness. He was called to follow Jesus, the Wisdom of God. He was not asked to make a donation from the profits of his business, but to follow in person.