And this is the way to have eternal life—to know you, the only true God, and Jesus Christ, the one you sent to earth. ~John 17:3
"Knowing" someone is to enter into a close relationship with that person.
John 15 talks about remaining in the Vine (Jesus). The Greek word for remain is "meno" which, according to my NLT Study Bible, means to remain/stay/abide. My Bible's study notes go on to say it means to have a "profound, intimate, enduring relationship."
"I pray that they will all be one, just as you and I are one—as you are in me, Father, and I am in you. And may they be in us." (John 15:21)"This mutual indwelling between God and the believer/disciple is not a fleeting or temporary commitment but an unending, permanent and eternal relationship."
God wants us to know Him.
Hosea 4:6 My people are being destroyed because they don’t know me. Since you priests refuse to know me, I refuse to recognize you as my priests.Knowing God, being one with Him, to me is a union that fills me with peace, with bliss. So when God says we are to love each other the same way He has loved us in the same passage that speaks about remaining in Him, well, it takes on a whole new meaning. Do we really have any idea what it is to love God, love ourselves, love each other? To have that intimacy, joy, peace, bliss in knowing God, ourselves, each other?
Hosea 6:3 Oh, that we might know the Lord! Let us press on to know him.He will respond to us as surely as the arrival of dawn or the coming of rains in early spring.”
Hosea 6:6 I want you to show love, not offer sacrifices. I want you to know me more than I want burnt offerings.