I will not leave you as orphans; I will come to you. Yet a little while and the world will see me no more, but you will see me. Because I live, you also will live. -- John 14:18-19 (ESV)

Jesus will return one day to collect God's children so that they can live with him and their Father.

In that day you will know that I am in my Father, and you in me, and I in you. -- John 14:20 (ESV)

When the Father, Jesus and believers live "in" each other, it means they are in close communion (fellowship). When we live in unity with the Father and the Son we will look and act the same.

Whoever has my commandments and keeps them, he it is who loves me. And he who loves me will be loved by my Father, and I will love him and manifest myself to him.”

Judas (not Iscariot) said to him, “Lord, how is it that you will manifest yourself to us, and not to the world?”

Jesus answered him, “If anyone loves me, he will keep my word, and my Father will love him, and we will come to him and make our home with him.”

-- John 14:21-23 (ESV)

Jesus continue in the next chapter to explain how this relationship work:

“I am the true vine, and my Father is the vinedresser. Every branch in me that does not bear fruit He takes away, and every branch that does bear fruit He prunes, that it may bear more fruit. Already you are clean because of the word that I have spoken to you. Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing. If anyone does not abide in me he is thrown away like a branch and withers; and the branches are gathered, thrown into the fire, and burned. If you abide in me, and my words abide in you, ask whatever you wish, and it will be done for you. By this my Father is glorified, that you bear much fruit and so prove to be my disciples. As the Father has loved me, so have I loved you. Abide in my love. If you keep my commandments, you will abide in my love, just as I have kept my Father’s commandments and abide in His love. -- John 15:1-10 (ESV)

In other words, when believers "abide in" Jesus or Jesus "lives in" believers, that does not turn them into Jesus. Likewise, Jesus does not turn into God when God lives in him or when he submits under God's authority and do His will or when people get to know the Father through the way Jesus presented the Father to them.

When used in the sense of “in God,” or “in Christ,” the word “in” refers to a close communion, a tight fellowship. It was part of the covenant language of the day, when people spoke of being either “in” or “cut off from” the covenant.

-- Morgridge, pp. 116 and 117
-- Racovian Catechism, pp. 142 and 143
-- Spirit & Truth Fellowship International

Jesus also prayed (not to Himself, but to the Father):

I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as You, Father, are in me, and I in You, that they also may be in us, so that the world may believe that You have sent me.

The glory that You have given me I have given to them, that they may be one even as we are one, I in them and You in me, that they may become perfectly one, so that the world may know that You sent me and loved them even as You loved me.

Father, I desire that they also, whom You have given me, may be with me where I am, to see my glory that You have given me because you loved me before the foundation of the world. O righteous Father, even though the world does not know You, I know You, and these know that You have sent me. I made known to them Your name, and I will continue to make it known, that the love with which You have loved me may be in them, and I in them.

-- John 17:20-26 (ESV)