Therefore he says, “Awake, you who sleep, and arise from the dead, and Christ will shine on you.”
The context of the false differences between Apostles and Prophets in Ephesians suggests that Paul is quoting one of the New Testament Prophets.
The false teachers in Ephesus were misinterpreting the prophetic word given by a New Testament prophet. They were saying that the Spirit of Christ was Lord of the dead and so would only shine on the Gentiles after they died.
Paul responds by saying all believers in Christ were dead in their sins but are now made alive in Christ (Eph. 2:1, Eph. 2:5).