Since we believe in Jesus' bodily resurrection from the grave after His crucifixion, then we also believe in the promise of our bodily resurrection into eternity. The alternative is to believe in nothing that is real, nothing that is hopeful or redeeming.
We cannot separate these truths. Jesus is the first fruits of those raised from the dead. When Paul says this in 1 Corinthians 15:20, he uses a verb tense in the Greek that means Jesus not only was raised but is still alive. He lives forevermore.
George Sweeting writes: "In Glendale, California, at Forest Lawn Cemetery, hundreds of people each year stand before two huge paintings. One pictures the crucifixion of Christ. The other depicts His resurrection. In the second painting the artist has pictured an empty tomb with an angel near the entrance. In the foreground stands the figure for the risen Christ. But the striking feature of that huge canvas is a vast throng of people, back in the misty background, stretching into the distance and out of sight, suggesting the multitude who will be raised from the dead because Jesus first died and rose for them."
Taken from "God's Plan For The Resurrection" by In Touch Ministries (used by permission).