They are one and so will we be one with them:You can't say they are two separate entities
Jesus said "My Father and I are one".
John 10:30;
"Neither pray I for these alone, but for them also which shall believe on me through their word;
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.
And the glory which thou gavest me I have given them; that they may be one, even as we are one:" John 17:20-22
Since we will be one with them according to Jesus' prayer, does that mean that God will be a plurality of many [a multiplicity] when we are all like him?
"Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is." I John 3:2