Apostle John, after pointing to the necessity of hope of seeing Christ motivate a life of active purity (3). Like Thomas Watson asserted. Who that "Till sin be bitter, Christ will not be sweet," John reminds the believers, on the need to use biblical vocabularies in defining sin: not only – as transgression against the law of God, as missing the mark of divine purity, as iniquity, as trespass, and ultimately as – unrighteousness. Apostle John continues defining the scourge of sin, also, as a lifestyle lived apart from God, or lawlessness, or rebellion. Sin as evil. Sin is wickedness, unbelief, error as well as being fundamentally, humanity's nativity. This is sin's plight (v4). In verses that follow, (v5–9); John testifies concerning the remedy for Sin, "the Savior." He gives two reasons "why" Jesus came: a) to take away sin (5), but also b) to destroy the works of the devil (7–8)." Therefore, he, whom the Son of man sets free, is free indeed.