There is no need to doubt the literal nature of Christ’s ascension, so long as we realize its purpose. It was not necessary as a mode of departure, for ‘going to the Father’ did not involve a journey in space and presumably he could simply have vanished as on previous occasions. The reason he ascended before their eyes was rather to show them that this departure was final. He had now gone for good, or at least until his coming in glory. So they returned to Jerusalem with great joy and waited – not for Jesus to make another resurrection appearance, but for the Holy Spirit to come in power, as had been promised.
—Understanding the Bible, 103.