The physical resurrection of the Lord, as this chapter states very directly, guarantees that Christians will also be raised with Him. This promise motives us to live in holiness even now, looking forward to our life with Him in heaven.
12 Now if Christ is proclaimed as raised from the dead, how can some of you say that there is no resurrection of the dead? 13 But if there is no resurrection of the dead, then not even Christ has been raised. 14 And if Christ has not been raised, then our preaching is in vain and your faith is in vain. 15 We are even found to be misrepresenting God, because we testified about God that he raised Christ, whom he did not raise if it is true that the dead are not raised. 16 For if the dead are not raised, not even Christ has been raised. 17 And if Christ has not been raised, your faith is futile and you are still in your sins. 18 Then those also who have fallen asleep in Christ have perished. 19 If in Christ we have hope in this life only, we are of all people most to be pitied. ~~1 Corinthians 15:12-19 (ESV)Without the prospect of living with Jesus in His eternal Kingdom, having Him atone for our sin seems pretty ridiculous. If nothing exists after this life, why bother with forsaking sin and trusting in Christ? As verse 19 says, without the resurrection and its promise that Christ will in turn raise us from the dead, Christians lead the most pathetic lives of all people!
Let's suppose, for a moment, that Christ's resurrection never happened. Consider the silliness of our Christian lifestyle. We deny our fleshly desires in obedience to Someone Whose sacrifice for sin ultimately failed to please His Father, and as a result, we do nothing but miss out on pleasures that our non-Christian counterparts enjoy. Why bother battling against sin? If the Incarnate God couldn't overcome sin, what makes us think we can atone for it? We might as well enjoy the party, indulging in whatever behaviors suit our fancy.
Thankfully, however, Jesus Christ did rise from the dead, opening the glorious promise that He will also raise us! In gratitude, I eagerly turn from the sin that offends His holy nature, joyfully anticipating the wonderful day when, in my resurrection body, I'll finally experience liberation from temptation. I'll be physically in His presence, worshiping Him without distraction or impurity. And I'll pity those who believed the fleeting pleasures of this life could satisfy them.