But whoever habitually keeps His word and obeys His precepts [and treasures His message in its entirety], in him the love of God has truly been perfected [it is completed and has reached maturity]. By this we know [for certain] that we are in Him:

I am writing to you, fathers [those believers who are spiritually mature], because you know Him who has existed from the beginning. I am writing to you, young men [those believers who are growing in spiritual maturity], because you have been victorious and have overcome the evil one. I have written to you, children [those who are new believers, those spiritually immature], because you have come to know the Father.

I have written to you, fathers, because you know Him who has existed from the beginning. I have written to you, young men, because you are strong and vigorous, and the word of God remains [always] in you, and you have been victorious over the evil one [by accepting Jesus as Savior].

and every spirit which does not confess Jesus is not of God. And this is the [spirit] of anti-christ, of which you have heard that he is coming, and he is now in the world already.

All wrongdoing is sin, and there is sin that does not lead to death [one can repent of it and be forgiven].