When offering the gospel, John Piper asks the question, “If you can have all the good things and blessings of Heaven, and God is not there, do you still want Heaven?”
The point of the question is to elicit what the desire of the individual is — does he want God, or merely the good things that God gives, without any real interest in God. And if you don’t want God, you don’t believe the gospel, because God is the Gospel.
Jonathan Edwards has said the same thing in different words:
Now the main reason why the godly man has his heart to heaven is because God is there; that is the palace of the Most High.…If God and Christ were not in heaven, [the godly man] would not be so earnest in seeking it, nor would he take so many pains in a laborious travel through this wilderness, nor would the consideration that he is going to heaven when he dies be such a comfort to him under toils and afflictions. The martyrs would not undergo cruel sufferings from their persecutors, with a cheerful prospect of going to heaven, did they not expect to be with Christ, and to enjoy God there.…The believer’s heart is in heaven, because his treasure is there.