A friend asked the question “what is this clothing all about? Is this clothing a tight or a loose fit...and what might be the power?”
I wonder if Luke is in any way picking up this clothing metaphor from Paul and the Pauline tradition?
In 2 Corinthians 5, clothing is a metaphor for a heavenly/eternal dwelling. In Galatians 3:27, disciples are clothed with Christ in baptism (also a prominent part of Pentecost, Acts 2:41). Additionally, the believer puts on armor of light (Romans 13:12), the full armor of God (Ephesians 6), the new self (Eph 4:24, Col 3:10).
Colossians 3 collects a number of these images and concepts in one place, where those who have been raised with Christ are instructed: “Do not lie to each other, since you have taken off your old self with its practices and have put on the new self, which is being renewed in knowledge in the image of its Creator. Here there is no Greek or Jew, circumcised or uncircumcised, barbarian, Scythian, slave or free, but Christ is all, and is in all. Therefore, as God's chosen people, holy and dearly loved, clothe yourselves with compassion, kindness, humility, gentleness and patience” (Col 3:9-12).
Both the Galatians and Colossians language about clothing imply that these new Christ-clothes cover up marks of difference (foreskin or circumcision, slave marks, sexual difference). The gift of tongues (or of understanding) given at Pentecost makes irrelevant the principal distinction among Jews gathered in Jerusalem.
“Clothed with power” might have something to do with the power that is made manifest when: 1) people find unity across dividing lines and 2) constitute a new identity rooted in the image of the Creator: righteous, compassionate, etc.
These clothes may not fit so comfortably on our old self. But for our new self, they are work clothes, Sunday-go-to-meetin’ clothes, and leisure-wear, perfectly tailored.