“Our Lord Jesus Christ consecrated for us a new and living way… it is not then that He may present Himself to God the Father, that Christ has ascended upon high; for ever was and is and will be continually in the Father, in the sight of Him Who begat Him, for He it is in Whom the Father ever takes delight. He ascended on this occasion as man, for a strange and unaccustomed manifestation the Word who of old was without humanity. For us and for our sakes He did this, in order that man that He was, He might hear addressed to Him in His wholeness as Son in power and with flesh, the words ‘Sit at my right hand‘ (Ps 109.1), and transmit the glory of sonship to the whole race through Himself… He manifested Himself as man, in order to set us once more in the sight of the Father, we who had gone from His gaze by reason the primeval transgression. He sat down as Son, that we too might be called sons though Him and children of God. For this reason also Paul, who insists that he has Christ speaking by His voice, teaches us to regard the events that happened in the Life of Christ alone as common to the whole race saying that God ‘raised us up with Him, and made us to sit with Him in the Heavenly places (Eph 2.6).'” St. Cyril of Alexandria, Commentary on John, On John 14.2-3.
Christ, Who is Divine and of One Essence with the Father, does not ascend for His own sake. He ascends that He may bring our humanity to the right hand of The Father. The True Son, before all ages, ascends so that we too may become sons and daughters. It is no accident that this event is separated from Pentecost by only 10 days for Pentecost is when The Spirit returns to adopt all humanity. Christ ascends to seat us at the right hand of The Father so that The Spirit might be able to return to the human being. By this adoption, we will be enfolded back into the Divine Life through adoption in The Spirit. This is intelligible in Orthodoxy only because the whole of salvation is viewed as a return to God, a ‘re-participation’ in the Divine Life, once again becoming ‘partakers of the Divine nature (2 Peter 1.4)’.