1 John 4:17-18 (KJV)
17 Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world.
18 There is no fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love.
The above verse written by apostle John was not penned down by impulse nor was it solely based on his own experience, as the Sum of the Word will reveal to us in this study.
Like all the prophets, it was all from the inspiration of the holy spirit of God, and they were moved to write it down for our admonition.
* update Oct 19, 2015: Part 6 added