Since we believe in Jesus' bodily resurrection from the grave after his death on the cross and 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. Read more from Charles Stanley's Christ's Resurrection Confirms Our Own?