This Sunday closes out Christmastide with the Baptism of the Lord, which is kind of like Epiphany, Part 2.
The Old Testament reading (Isaiah) is an invitation, God's call to come back to those of us who have tried to do things on our own and had it turn into a mess. Instead of an “I told you so,” God’s response when we come back is a forgiveness more generous than we could ask for or imagine. And God’s forgiveness is the driving force behind the rest of this Sunday’s readings.
The Epistle (Acts) tells us that the door is open to everyone in God’s plan of salvation (which is part of what makes this Sunday Epiphany, Part 2). And Peter shows us what this means in practice, by including soldiers in the foreign army occupying Peter’s home town.
The Gospel (Mark) brings back John the Baptist and his odd way of describing the one who was to come after him (about not being worthy to untie his sandals), and shows us the actual Baptism of Jesus. Okay, but how is this Epiphany, Part 2? Because it shows us the beginning of Epiphany put into practice.
Readings for Sunday: http://www.usccb.org/bible/readings/011115.cfm