It's a striking image. The beam of light spotlights the table of greedy tax collectors young and old, hunched over a table of money. Only the three on the right side have even noticed Jesus's presence; the other two still focus on the little metal pieces in front of them. But that beam of light slices through the shady room as directed by Jesus's Creation of Adam style finger at Matthew. That thin delicate halo is the only part of this work that couldn't truly be found in some crusty back room somewhere. It's mystical, but mystical within the bounds of reality which, for many, makes the image all the more powerful. The man in the middle looks at Jesus with a startled expression, pointing at himself as if to say "who me?" Or maybe he's pointing at one of the men to his side. There are many interpretations of this, but to me, his ambiguity seems intentional and serves to further his point. A sinner, a nondescript nobody, being called to God shows the world that important lives are not restricted to the people on top. Caravaggio argues quite convincingly with his painting that anybody can be called. The men around those tables may as well be you, me, a drunk passed out at a bar, or even the guy who cut you off in traffic. Caravaggio's focus in The Calling of St. Matthew is not on a blinding Jesus, glowing with the light or God and salvation, it is on the man, the everyday-Joe-type sinner experiencing a transformation. Jesus is merely a facilitator of God's will. It shows a world where we don't worship the man doing the blessing, we're worshiping the force and that force is streaming out to cover the layman.