7 We must journey on then, yet for this no need of anointing the feet, or looking out for beasts, or providing a vessel. Run with the heart's affection, journey on with love, ascend by charity. Why do you seek for the way? Cleave unto Christ, who by Descending and Ascending has made Himself the Way. Do you wish to ascend? Hold fast to Him that ascends. For by your own self you can not rise. “For no man has ascended up to heaven, but He that came down from heaven, even the Son of Man which is in heaven.” If no one ascends but He that descended, that is, the Son of Man, our Lord Jesus, do you wish to ascend also?
Be then a member of Him who Only has ascended. For He the Head, with all the members, is but One Man. And since no one can ascend, but he who in His Body is made a member of Him; that is fulfilled, “that no man has ascended, but He that descended.” For you can not say, “Lo, why has Peter, for instance, ascended, why has Paul ascended, why have the Apostles ascended, if no one has ascended, but He that descended?” The answer to this is, “What do Peter, and Paul, and the rest of the Apostles, and all the faithful, what do they hear from the Apostle? 'Now you are the Body of Christ, and members in particular.' If then the Body of Christ and His members belong to One, do not make two of them.
For He left 'father and mother, and clave to his wife, that two might be one flesh.' He left His Father, in that here He did not show Himself as equal with the Father; but 'emptied Himself, taking the form of a servant.' He left His mother also, the synagogue of which He was born after the flesh. He clave to His Wife, that is, to His Church. Now in the place where Christ Himself brought forward this testimony, He showed that the marriage bond might not be dissolved: 'Have ye not read,' said He, 'that God which made them at the beginning, made them male and female; and said, They two shall be in one flesh?
What therefore God has joined together, let not man put asunder.' And what is the meaning of 'They two shall be in one flesh'? He goes on to say; 'Wherefore they are no more two but one flesh.' Thus 'no man has ascended, but He that descended.'”
Source: Sermons on Selected Lessons of the New Testament (New Advent)