The thrust of Paul's exhortation is to encourage us to quit looking back with longing to the world and our former lives and to live in the present with our minds focused with eager and active expectation on our Savior's return. If we are doing these things, we are preparing for that future great event. Eagerly anticipating the imminent fulfillment of our earnest desire for Christ's return motivates us to modify our conduct in the present evil world.

If we do not have this glorious hope in us, we will very likely just drift around, squandering our time in useless, trivial, but perhaps exciting carnal pursuits. We will fail to use the grace of God toward growing in His image and producing fruit.