He can sympathize with us
The ascension means we have a high priest in heaven who can sympathize with our weaknesses because he once bore our human lot. First, we say that there’s a human nature in heaven. When God came to this earth, He took upon himself a human nature. That human nature was thrown into the pyres of Calvary in reparation for the sins of man; it rose and now ascends. There is a continuity between the Incarnation and the ascension. In the Incarnation our Lord took a body, yes, but not just a body to suffer. Otherwise he would have taken it for only a time. If he took that human nature just in order to suffer for our sakes, why did he not divest himself of that human nature? After all, his garments had been soiled and stained. They had borne the heat and burdens of the day. Why not throw them off? Christ's human nature was taken not just to atone for our sins. The end and purpose of God coming to earth was to bring us to perfect union with the Father. How could he do this? He could do it by showing that our flesh is not a barrier to that intimacy, by taking it up to heaven itself, and by showing that those who pass through trials and suffering in this life will have their body glorified. By sharing in Christ’s cross we share in his glory. The goal of all humanity is in some way reached in the Ascension.