C.S. Lewis not only awakens our desire for heaven, he argues convincingly for its existence.
Every natural desire has a corresponding object that can satisfy that desire. “A baby feels hunger: well, there is such a thing as food. A duckling wants to swim: well, there is such a thing as water.”
There exists within each of us a desire that nothing in our experience can satisfy. Lewis says it's the secret we cannot hide and cannot tell. “We cannot tell it because it is a desire for something that has never actually appeared in our experience. We cannot hide it because our experience is constantly suggesting it….”
Therefore there exists something outside our experience which can satisfy the desire. “But if it should really become manifest — if there ever came an echo that did not die away but swelled into the sound itself — you would know it. Beyond all possibility of doubt you would say ‘Here at last is the thing I was made for’.”
“I have come home at last! This is my real country! I belong here. This is the land I have been looking for all my life, though I never knew it till now. The reason why we loved the old Narnia is that it sometimes looked a little like this. Bree-hee-hee! Come further up, come further in.” Jewel, the Unicorn in "The Last Battle" by C.S. Lewis
C.S. Lewis observed that human beings respond to this longing in one of three ways.
The fool's way is to seek experience after experience without satisfaction. “He goes on all his life thinking that if only he tried another woman, or went for a more expensive holiday, or whatever it is, then, this time, he really would catch the mysterious something we are all after.”
The sensible person's way is to become disillusioned, giving up any hope of satisfaction. “He soon decides that the whole thing was moonshine…. And so he settles down and learns not to expect too much and represses the part of himself which used, as he would say, ‘to cry for the moon.’ ”
The Christian way says, “If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world."
“Probably earthly pleasures were never meant to satisfy it, but only to arouse it, to suggest the real thing…. I must keep alive in myself the desire for my true country…. I must never let it get snowed under or turned aside; I must make it the main object of life to press on to that other country….”