Satan is enraged that God has entitled us to the home that he was kicked out of (Is. 14:12-15). Knowing that God has set eternity in men’s hearts, he doesn’t usually try to convince us that heaven doesn’t exist. Instead, he’s convinced most that heaven is a place of boring, unearthly existence – like an endless harp recital. Paul commands us to “set our hearts” in a diligent, active, single-minded quest to understand heaven. When we understand where we are going, it brings into focus how best to get there (v. 5-17).
“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