'Known' in the Bible

I am writing to you, fathers, because you have known the one who has existed from the beginning. I am writing to you, young people, because you have overcome the evil one.

I have written to you, little children, because you have known the Father. I have written to you, fathers, because you have known the one who has existed from the beginning. I have written to you, young people, because you are strong and because God's word remains in you and you have overcome the evil one.

No one who remains in union with him keeps on sinning. The one who keeps on sinning hasn't seen him or known him.