He did not leave heaven when he came down to us; nor did he withdraw from us when he went up again into heaven. The fact that he was in heaven even while he was on earth is borne out by his own statement: No one has ever ascended into heaven except the one who descended from heaven, the Son of Man, who is in heaven. These words are explained by our oneness with Christ, for he is our head and we are his body. No one ascended into heaven except Christ because we also are Christ: he is the Son of Man by his union with us, and we by our union with him are the sons of God. So the Apostle says: Just as the human body, which has many members, is a unity, because all the different members make one body, so is it also with Christ. He too has many members, but one body. Out of compassion for us he descended from heaven, and although he ascended alone, we also ascend, because we are in him by grace. Thus, no one but Christ descended and no one but Christ ascended; not because there is no distinction between the head and the body, but because the body as a unity cannot be separated from the head.