“For this reason it says, ‘Awake sleeper, and arise from the dead, and Christ will shine on you’” (Ephesians 5:14).
Some think Paul is freely adapting Isaiah 60:1 in this verse; others, that he is quoting an early hymn. Regardless, his point is that those who are spiritually asleep need to wake up and let the Son shine on them. Toward that end, he is encouraging Christians to live in such a way as to be lights, exposing wrong by both our instruction and our example. “For you were formerly darkness, but now you are Light in the Lord; walk as children of Light” (v. 8)
Sometimes, Christians themselves need to wake up. Paul wrote to the brethren at Rome: “Do this, knowing the time, that it is already the hour for you to awaken from sleep; for now salvation is nearer to us than when we believed. The night is almost gone, and the day is near. Therefore let us lay aside the deeds of darkness and put on the armor of light. Let us behave properly as in the day. . .” (13:11-13a).
Similarly, Jesus said to some Christians at Sardis, “Wake up, and strengthen the things that remain, which were about to die; for I have not found your deeds completed in the sight of My God” (Revelation 3:2). Those of us who are still clinging to old sinful attitudes or behaviors need to wake up! So do those who are sleepwalking—just going through the motions of Christianity, with little zeal or enthusiasm doing only the least we can get by with.
“Behold, I am coming like a thief. Blessed is the one who stays awake and keeps his garments . . .” (Revelation 16:15).