"If you read history you will find that the Christians who did most for the present world were just those who thought most of the next. The Apostles themselves, who set on foot the conversion of the Roman Empire, the great men who built up the Middle Ages, the English Evangelicals who abolished the Slave Trade, all left their mark on Earth, precisely because their minds were occupied with Heaven. It is since Christians have largely ceased to think of the other world that they have become so ineffective in this. Aim at Heaven and you will get earth "thrown in": aim at earth and you will get neither.”
- C.S. Lewis 

Whom have I in heaven but You?
And besides You, I desire nothing on earth.
My flesh and my heart fail,
But God is the strength of my heart and my portion forever.
For, behold, those who are far from You will perish;
You have destroyed all those who are unfaithful to You.
But as me, the nearness of God is my good;
I have made the Lord God my refuge,
That I may tell of all Your works.

Earth holds no treasures
But perish with using,
However precious they be;
Yet there’s a country
To which I am going:
Heaven holds all to me.

Why should I long
For the world with its sorrows,
When in that home o’er the sea,
Millions are singing
The wonderful story?
Heaven holds all to me.

Heaven holds all to me,
Brighter its glory will be;
Joy without measure
Will be my treasure:
Heaven holds all to me.

...

 Turn your eyes upon Jesus,
Look full in His wonderful face,
And the things of earth
Will grow strangely dim
In the light of His glory and grace.