...I believe, the necessity for the conversion is inexorable; at least, if our natural loves are to enter the heavenly life. That they can enter it most of us in fact believe. We may hope that the resurrection of the body means also the resurrection of what may be called our "greater body"; the general fabric of our earthly life with its affections and relationships. But only on a condition; not a condition arbitrarily laid down by God, but one necessarily inherent in the character of Heaven: nothing can enter there which cannot become heavenly. "Flesh and blood," mere nature, cannot inherit that Kingdom. Man can asend to Heaven only because the Christ, who died and ascended to Heaven, is "formed in him." Must we not suppose that the same is true of man's loves? Only those into which Love Himself has entered will ascend to Love Himself. And these can be raised with Him only if they have, in some degree and fashion, shared His death; if the natural element in them has submitted - year after year, or in some sudden agony - to transmutation. The fashion of this world passes away. The very name of nature implies the transitory. Natural loves can hope for eternity only in so far as they have allowed themselves to be taken into the eternity of Charity; have at least allowed the process to begin here on earth, before the night comes when no man can work. And the process will always involve a kind of death. There is no escape. In my love for wife or friend the only eternal element is the transforming presence of Love Himself. By that presence, if at all, the other elements may hope, as our physical bodies hope, to be raised from the dead. For this only is holy in them, this only is the Lord.C.S. Lewis is not just talking about the life to come, but this present life as well, as we see in carefully reading this, in showing how the natural loves which are part of God's good creation, even though corrupted by the fall in humanity's sin, can partake of the heavenly life of God even now. When they don't they are doomed not only in the life to come, but in this present life, to not fulfill their purpose for existing. But when they partake of this heavenly life in Jesus, they can begin to fulfill that purpose even here and now, not perfectly, but certainly and substantially in the holy love of Love Himself.
quote from The Four Loves, by C.S. Lewis (pages 136-137)