John 17
11 And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
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21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
22 And the glory which thou gavest me I have given them; that they may be one, even as we are one:
23 I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me.
As a former POTUS once said, "It depends on what the meaning of is is.", or something like that.
Jesus gave to ‘them’ the same thing that He had within His human spirit, The Holy Spirit. Jesus walked the Earth as a man, God as a man indwelt by the Holy Spirit of God, thus Jesus is The Man-God, as the Holy Spirit is The Spirit-God, and The Father is Almighty-God. That same indwelling Holy Spirit makes the Saved one with Him by the same Holy Spirit, else Jesus would not have told the lowly Apostles ‘greater works/miracles will you do’.