It is not uncommon for a teacher to alert a child with the need to 'wake up'.  Although some pupils may be physically asleep, the meaning is a clear warning to day-dreamers that a disaster is around the corner unless action is taken soon.  This quote, about the sleeper needing to wake up, has echoes of Isaiah 26:19; 51:17; 52:1; 60:1, but none of them have the full text quoted.  So, it might be a baptismal exhortation or an early Christian hymn. Whichever, the meaning is clear: the Christian who is sleepwalking in sin needs to wake up and walk in the Light.

'The light' is a Bible metaphor for the truth that comes from God and is contained in the Scripture (Psalm 119:105).  When Jesus was born He was described as a 'Light to the Gentiles' by Simeon (Luke 2:32) and Jesus called Himself the Light of the world (John 8:12).  Peter therefore says that Jesus validates the Old Testament prophets whose light pointed forwards to Him (2 Peter 1:16-19).

To ignore that truth, or to assume it does not apply to you, is deadly.  By contrast, to wake up to truth is to come alive to the Lord.  The wider we open the eyes of our hearts, the more we will see - because the light of Christ will illuminate everything now or expose everything when He returns (1 Corinthians 3:13).  We will be able to see how stupidly unproductive is our sinful ('dead') behaviour; and we will be able to appreciate the privilege of walking in fellowship with the Lord again.

Alas, it is not uncommon for the apparently 'spiritual' Sunday-Christian to become just like the spiritually-dead around them at work on Monday.  All the traps that are laid for the Christians are intended to neutralise the Jesus-difference in our lives.  Here are some of them: the pressure to conform, the relative absence of believers to hold us to account, the regular temptations to dishonesty and impurity, and the gossipy or blasphemous language style.  Away from home and away from church, we can be tempted into thinking that nobody notices.  But they do!  God is disappointed, and the devil is thrilled when we sleep walk into compromising our integrity, holiness and heavenly reward.  So: wake up today.  Ask the Lord to reveal to you which truth you need to obey; and then ask Him to help you to change direction so that you are walking towards heaven - with the freedom that comes from forgiveness and the confidence that comes from God's pleasure.