1 John 3:3

1 John 3:3. And every one that hath this hope set on him purifieth himself, even as he is pure. That the ‘calling' and the ‘being,' the privilege and the reality, may be hereafter eternally one and indistinguishable, the children of God must in this life become like the Son in His purity: the Divine gift will be consummated as a gilt when the Son is revealed; but it is consummated in this world not without human co-operation. Here alone St. John calls in the energy of Christian hope: its object is the appearing of Christ, it is ‘set on Him;' within the soul it is an incentive: the faith which worketh by love worketh by hope also. The meaning of the word ‘purifieth himself' will best be understood by collating it with ‘doeth righteousness:' the latter is a complete conformity with the requirements of law, the former is the deliverance from all interior sin; the latter is our finished justification, the former is our entire sanctification. Christ is the standard of both: ‘even as He is righteous,' ‘even as He is pure.' Neither the one nor the other connotes the idea that He became what He is. ‘He is pure,' and that is the same as saying that the Divine holiness is essentially in Him. ‘Be ye holy, for I am holy.' That He is called ‘pure' and not ‘holy' has two reasons. First, it springs from the idea of our ‘purifying ourselves.' Secondly, it is more limited than ‘holy,' and refers to His human nature as free from the stain that all other human nature has. It is never used of God, but is strictly appropriate to God incarnate. Then our purifying ourselves has reference to the gradual attainment of that entire deliverance from the stain of sin not unchastity or any specific form of it which is represented in the first chapter as the effect of Christ's blood. The word there used St. Paul adopts to express our own evil: ‘Let us cleanse ourselves from all defilement.' St. John keeps that for the Divine work, and uses a term which St. Peter and St. James agree with him in adopting for the human act: ‘Seeing ye have purified your souls' (1 Peter 1:22); ‘Purify your hearts, ye double-minded' (James 4:8).

Regeneration and sinning incompatible: first considered with reference to our union with Christ as manifested to take away sin, and our true knowledge of Him; and then secondly with reference to the utter abolition of our fellowship with the Devil.