Greek Question: "to the ones being [in Ephesus?]"

We were translating the first part of Ephesians in my Greek Reading class the other day and I was suddenly struck by the words τοῖς οὖσιν (Greekish: “to the ones being”) in verse 1. You may know that there is a debate about whether Paul wrote Ephesians, and related to that question is whether the [...]