From:
The Quotable SpurgeonHomesick for Heaven’s GloriesI consider that our present sufferings are not worth comparing with the glory that will be revealed in us. The creation waits in eager expectation for the sons of God to be revealed. For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope that the creation itself will be liberated from its bondage to decay and brought into the glorious freedom of the children of God. We know that the whole creation has been groaning as in the pains of childbirth right up to the present time. Not only so, but we ourselves, who have the firstfruits of the Spirit, groan inwardly as we wait eagerly for our adoption as sons, the redemption of our bodies. For in this hope we were saved. Romans 8:18-24
Have you ever seen a caged bird with its breast or wing bleeding from blows received by dashing against the wire of its cage? The poor creature dreamed of the forest and of the craggy rock, and, filled with aspirations for most sublime flight, it stretched its wings and flew upward, only to bring itself into sharp contact with its prison. Even thus the new-born nature, stirred in its inmost depths with longings suitable to its celestial origin, aspires after the joys of heaven, stretching all its wings to war toward perfection. But we who are in this body do groan; we find the flesh to be a prison, and so the more we long the more we pine. And pining, we sigh and cry, and wound our hearts with insatiable desires and bleeding discontents. The pangs of strong desire for the presence of the Lord in glory—who among believers has not felt them? Who among us has not found our flight upward brought to a painful pause by the stern facts of flesh and blood, and earth and sin?