1 John 2:12-17
Chapter 2
Fathers, I write this to you: you know him who is from the beginning. Young people, I write this to you: you have overcome the evil one.
My dear children, I write to you because you already know the Father.
Fathers, I write to you because you know him who is from the beginning. Young people, I write to you because you are strong, and the word of God lives in you who have, indeed, overcome the evil one.
Do not love the world or what is in it. The love of the Father is not in those who love the world.
For everything in the world—the craving of the flesh, the desire of the eyes, and people bragging about their superiority—all this belongs to the world, not to the Father.
The world passes away with all its cravings, but those who do the will of God remain forever.

Commentaries
Overcoming the Evil One.
Overcoming the evil one also means overcoming the world—from the Johannine perspective—which “belongs to the evil one” (5:19) and dominates the powers acting within it. The world can be broken down into these three powers: “The evil desires of human nature” (cf. Jn 3:6; Eph 2:3; 1 Pt 2:11), the “lust of the eyes” (3:17; cf. Jas 4:16), and the “pride of riches.” For the believer, victory over both the world and the evil one is a gift from Christ, but it is also a task: “an indication” (2:13; 4:4; 5:4) and “an imperative” (15a). There is no middle ground, no alternative: either the love of the Father or the love of the world (15b; cf. Jas 4:4; Mt 6:24).