What does Paul mean by bearing the image of the earthy?
Paul means believers have shared Adam's earthly, fallen condition—sons of Adam, flesh and blood under the curse. Through resurrection, they will also bear the heavenly image, moving from the natural state to the spiritual state. This requires a new body, for flesh and blood cannot inherit God's kingdom.
Les explains that verse 48 contrasts things that are earthy with things that are heavenly. In verse 49, bearing the image of the earthy means we are sons of Adam, flesh and blood, under the curse; it is around us everywhere we go. Yet as we have borne that image, we shall also bear the heavenly image, moving from the natural state to the spiritual state. Verse 50 shows flesh and blood cannot inherit the kingdom of God, neither does corruption inherit incorruption. Therefore a new body is necessary, fashioned after Christ's body, especially after the resurrection. That is our hope: a glorious body not contained by walls, ceilings, or space. Les also notes possible pleasures like eating, since Christ ate on the shores of Galilee. Paul lays this out to establish basic doctrine, especially for Gentiles.
And as we have borne the image of the earthy, we shall also bear the image of the heavenly.