"If only for this life we have hope in Christ, we are of all people most to be pitied. But Christ has indeed been raised from the dead." — 1 Corinthians 15:19-20
Scripture abounds with examples of what I call the Divine Adversative. This is about God intervening to reverse the effects of our sin.
Yesterday we noted an example of this in the resurrection of Jesus. Christ's resurrection has reversed everything! Life conquered death, good conquered evil, and love conquered all.
As Paul explains, if Christianity is no more than a "feel-good" faith that helps us behave better in this life, we're pathetically hopeless. If that is the case, then we have no help from God in this life and no hope for the next, if there is life after death. So it would be better to abandon all hope for ourselves as well as for those who've already died. All of this would mean the resurrection is merely a figment of desperate faith.
But then comes the thunderous Divine Adversative: "But Christ has indeed been raised from the dead, the firstfruits of those who have fallen asleep." Hallelujah! We have a hope that extends from our life here on earth to eternity itself. Rather than being defeated by the curse of sin and death, "in Christ all will be made alive," just as Christ himself is alive for eternity.
All of our hope—and indeed all of our life—is certain, because God said, "But Christ!"