As is the earthy - Such as Adam was.
Such are they also ... - Such are all his descendants; all who derive their nature from him. That is, they are frail, corruptible, mortal; they live in an animal body as he did, and like him, they are subject to corruption and decay.
And as is the heavenly - As is he who was from heaven; as is the Lord Jesus now in is glorified body. “Such are they also, etc.” Such will they be also. They will be like him; they will have a body like his. This idea is more fully expressed in Philippians 3:21, “Who shall change our vile body, that it may be fashioned like unto his glorious body.”