From the Pope’s homily at the Chrism Mass:
Dear brothers and sisters,
the Russian writer Leo Tolstoy tells in a little story about a severe ruler who asked his priests and wise men to show God to him, so that he could see him. The wise men could not satisfy this desire at all. Then a shepherd, who had just come from the fields, offered to take on the task of the priests and sages. He told the king that his eyes were unable to see God. But then, the king wanted to know at least what things God does. “In order to answer your question,” said the shepherd to the sovereign, “we will have to exchange clothes.” With hesitation, but intrigued with curiosity, the sovereign agreed; he turned over his regal vestments to the shepherd and dressed himself in the simple clothing of a poor man. And then came the answer: “This is what God does.” In fact, the Son of God – very God of very God – left behind his divine splendor: “…he emptied himself, taking on the condition of a slave; being born in the likeness of man, he humbled himself… even to death on a cross.” (cf. Phil 2:6ff). God has — as the Fathers say — completed the sacrum commercium, the holy exchange: he has taken on that which was ours, in order that we may receive what was his, to become similar to God.