I write to you, fathers, because you know him who is from the beginning. I write to you, young men, because you have overcome the evil one. I write to you, little children, because you know the Father.
But that's just an addition to the text; you notice it's in italics. Which indicates it to be an addition to the text, and they're just trying to complete the thought, but the thought is complete enough without their addition. "Whosoever denies the Son has not the Father."