What does 1 Peter 5:13 mean?

Peter greets the Christian churches of Asia Minor on behalf of "she who is in Babylon." Some scholars speculate that Peter may have been referring to his wife. And yet, most agree this "she" is more likely another local church, probably the Christian church in Rome.

Why Rome? For one thing, it is unlikely there was any church in the historical city of Babylon at this time. And, it is very likely Peter was writing this letter from Rome. Also, Peter's Jewish readers would recognize "Babylon" as the traditional metaphor for those opposed to God's people. Rome, in that time, was the geographical and political source of that opposition. Peter may have been protecting the Christians in Rome by using Babylon as a stand-in.

In any case, Peter affirms that those Christians who are with him have been chosen by God for His purposes. The same applies to the Christians who would read his letter: they have been chosen. This connects the end of his letter to the beginning (1 Peter 1:2). Believers around the world share a common a sense of their belonging to the family of God and being set aside for His specific purposes. This is true no matter how their specific circumstances differ.

Finally, Peter offers greetings from Mark, whom he refers to as a "son." Most likely, this means a son in the faith and not his actual child. This is very likely the same Mark, also known as John Mark, the cousin of Barnabas, who travelled and ministered with Paul. In Colossians, Paul mentions that Mark was with him in Rome (Colossians 4:10), adding to the idea that Peter was likely writing from Rome.