Deceiving people to believe in the opposite of what the Bible says and then turning around and saying to them “it was only a joke”, is compared to a maniac. What is a maniac?
The words “light” and “night” refer to either being in the truth or still being blind, not knowing the Lord Jesus Christ. It can also mean that a Christian could be living in sin or not busy doing God’s will and thus “asleep” spiritually.
As followers of Jesus Christ, we are no longer to walk (live our life) in sin the way we did before our transformation by the indwelling of the Holy Spirit.
Jesus has saved us from darkness, deep darkness, who are the powerful forces that are keeping the world under their power and authority to do the devil’s will (2 Timothy 2:26).