In John 17: 20-23, Jesus says, “I do not pray for these alone [the twelve], but 1also for all those who will believe in (trust in, cling to, rely on) Me through their word; 21 that 2they all may be one, as You, Father, are in Me, and I in You; that 3they also may be one in Us, that the world may believe that You sent Me. 22 And the glory which You gave Me I have given them, that 4they may be one just as We are one: 23 I in them, and You in Me; that 5they may become one and perfectly united, and 6that the world may know that 6aYou have sent Me, and 6b[You]have loved them as You have loved Me.” I have a few things to say about this passage:
1] Jesus said He’s not praying for the  disciples alone, but also all those who would believe in Him because of their [the disciples’] words (and their teaching). I’m pretty sure that includes US, you and me.
2] That they would all be one. That means that all who believe in, trust in and rely on Jesus, will be one with each other. Unity of all of us who believe in Jesus
3] They also may be one in Us. That means we (all of us together) will be one in God and Jesus. How much closer to God can we get?
4] They may be one just as We are one. That means that we (the believers) may all be one in the same way that God and Jesus are one.
5] They may become one and perfectly united [us united with each other].
6] That the world may know that 6aYou have sent Me, and 6b[You]have loved them as You have loved Me. So the world may know that God sent Jesus, AND that God loves us (you and me and all of us), the same way and the same amount He loves Jesus.
Welp, I don’t know about y’all, but for me, if Jesus prayed it, you can write down in your book, because it’s going to happen. Some people might say it is going to happen when we all get to heaven, BUT some might say it is going to happen while we are still down here on the earth. All I know is I’m going to be grinning real big when these words comes to pass. And I’m looking forward to experiencing what it feels like to be united with God and each other the way God and Jesus are united. Hallelu-Jah! What if, here and now, we totally surrender our selves (our self-ish, sinful nature) and let Jesus fill us with His own Spirit. Do you think that might be the time when this One-ness starts to happen?