Light and darkness, Spirit and flesh.
References:
The Bible Exposition Commentary vol.2 - Warren W. Wiersbe
Believer's Bible Commentary - William MacDonald
The Freedom & Power of Forgiveness - John MacArthur
The Epistles of John - Marshall The Epistles of John - John R. W. Stott
The Joy of Fellowship, A Study of John - J. Dwight, Pentecost
The Freedom & Power of Forgiveness - David Augsburger
