Athanasius of Alexandria — as excerpted in the Catena Aurea on Luke 18:18-23

“(ex Apol. de sua fuga.) For when we despise the world, we must not imagine we have resigned any thing great, for the whole earth in comparison of the heaven is but a span long; therefore even should they who renounce it be lords of the whole earth, yet still it would be nothing worth in comparison of the kingdom of heaven.”