One dumb thing we occasionally hear is that we can be “so heavenly minded that we’re no earthly good.” It figures that this quip, which belongs in the same closet with falsehoods like “God helps those who help themselves,” was attributed to the atheist Oliver Wendell Holmes.
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 â€˜thrown inâ€™: aim at earth and you will get neither. -C.S. Lewis from Mere Christianity, Hope
The Apostle Paul says:
If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. 2 Set your minds on things that are above, not on things that are on earth. 3 For you have died, and your life is hidden with Christ in God. 4 When Christ who is your life appears, then you also will appear with him in glory. -Colossians 3:1-4
And because of your heavenly-mindedness, Paul goes on to say, put to death your sins. Heavenly-mindedness should lead to earthly good.