[Jhn 17:3-5 KJV] 3 And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent. 4 I have glorified thee on the earth: I have finished the work which thou gavest me to do. 5 And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.

Jesus existed before the world. He always existed as 1 Person of the Godhead.