St. John says that “No one who sins has seen him or known him.” But St. Paul says “all have sinned and fall short of the glory of God.” And the Preacher says, “Indeed, there is not a righteous man on earth who continually does good and who never sins.” Are Christians sinners or not? We are sinners. St. John himself wrote, in this same letter, “If we say we have no sin, we deceive ourselves, and the truth is not in us.” So then does no one know Jesus? Has no one seen Jesus? Certainly they have! St. John himself wrote, in this same letter, “What we have seen with our eyes. For the life was made visible; we have seen it and testify to it.”
What are we to say then? St. John contradicts himself. He knew Jesus. He saw Jesus. And he still sinned. Perhaps he does not mean something as absolute as it sounds. Perhaps he means to the extent that we know Jesus, we will not sin. If we do not know Jesus at all, we will sin a lot. If we know Jesus a little bit, we will sin less. If we know Jesus rather well, we will only sin a little. And when we know Jesus perfectly, we will not sin at all.
We will not know Jesus perfectly in this life. Not even the apostles and other disciples knew Jesus perfectly. Only his mother had that kind of knowledge of her son. But there will come a day when we do see Jesus face to face. On that day we will see him as he is. Then we will be like him: sinless.
St. John is expressing the relationship between seeing and knowing and being like. When we see a friend use a new cell phone that is better than ours, we want to be like them and have that phone too. When an athlete sees a star athlete run faster and comes to know how he does it, he imitates the star. When a cook tastes a steak that is better than they have ever cooked and they come to know the recipe, they will use that recipe in the future. When we see something better than our current situation, we imitate it. How much more, when we see the perfect man – Jesus Christ – and come to know him better, will we imitate him in every way.