The Apostle John’s interlude of encouragement, found in 1 John 2:12-14, is remarkable. There, he addresses all layers of the church’s population, beginning with a general address to the whole church [little children], then directing his comments to the elderly as well as the youth. As Simon Kistemaker puts it in the New Testament Commentary:
“John appeals to his readers and summarizes his thoughts in poetic form. He addresses his readers according to categories: first, all the believers receive his exhortation; next he appeals to the fathers and then to young men.”
In particular, I find it quite interesting that John repeats himself the most when addressing the elderly element of his audience. In fact, he repeats himself word-for-word when addressing this group, as follows:
13. I am writing to you, fathers, because you know Him who has been from the beginning.
14. I am writing to you, fathers, because you know Him who has been from the beginning.
Why such repetition? I agree with those who remind us that repetition in Scripture normally has the design of strengthening the emphasis of a matter. Thus, why does John offer an exact repetition to fathers? I would suggest that his point is to herald the seriousness of what he says about the true essence of Christian maturity. It is as if John is saying: “contentment in Christ alone is the sign of Christian maturity.” In many respects, it calls to mind the Lord’s teaching given when Philip requested that Jesus “show us the Father”:
Philip said to Him, “Lord, show us the Father, and it is enough for us.” Jesus said to him, “Have I been so long with you, and yet you have not come to know Me, Philip? He who has seen Me has seen the Father; how can you say, ‘Show us the Father’? John 14:8-9
What Philip did not yet understand was that he did see the fullness of the Father’s glory, through Christ, and it is enough. I would suggest that John’s point in 1 John 2 is quite simple, yet deeply profound: mature Christian faith confesses, with deep satisfaction, “I know the Father through the eternal Son of God – and it is enough.” In fact, such knowledge of the Father, through the eternal Son, is so satisfying that it is worthy of such repetition. We see such contentment in the life of John’s own student: Polycarp. Before his martyrdom, Polycarp confessed this same sense of contentment after being exhorted to renounce the eternal Son of God:
“Eighty and six years have I served him, and in nothing hath he wronged me; and how, then, can I blaspheme my King, who saved me?”
The simplicity of Polycarp’s confession is both beautiful and breathtaking. To know Christ is everything – it is enough – which is the very same lesson given to us from Polycarp’s mentor: the Apostle John. Of course, when John refers to such knowledge he does not mean a mere abstraction of thought or head knowledge. Instead, John’s frequent use of the word know (γινώσκω) is key to our understanding of what it means to love the God who first loved us in His eternal Son. When John speaks of the Christian’s knowledge of God, he is expanding on the central essence of what it means to love God truly. This point is very important because John’s 1st century audience was well aware of the Greek emphasis on erotic and hedonistic love. Such love was devoid of any relationship with others, but only had the focus of one’s self-pleasure and desire. Thus, the crucial distinction of the term love (ἀγάπη), as opposed to hedonistic love (ἔρως, ἡδονή), was that of the core idea of a relationship, i.e., to know someone truly and intimately. All of this points us to the essence of genuine maturity – to know and love the Father by knowing and loving His eternal Son, and to say, with repetition and great satisfaction: it is enough, because He is enough.
 Simon Kistemaker, New Testament Commentary, 1 John (Baker Books, Grand Rapids Michigan, 1986), pp. 267-269.
 Three times the Apostle Paul tells us of the inability of a man’s works to yield the fruit of justification. God’s repetition, through Paul, is quite telling: Galatians 2:16 (NASB) — 16 nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, that we may be justified by faith in Christ, and not by the works of the Law; since by the works of the Law shall no flesh be justified.
 1 John 4:19 (NASB) — 19 We love, because He first loved us.