The bodily resurrection of Jesus Christ is essential because it proves everything the gospel claims.
It confirms Jesus as the true Messiah, the very sign he promised to give. It shows that his atoning work was fully accepted, that the ransom for sin was paid, and that we are justified. His resurrection gives believers new spiritual life, uniting us to Christ as those who are “risen with Him.” And it provides the certain guarantee of our own future resurrection, removing the fear of death.
In short: If Christ did not bodily rise, we have no Savior, no forgiveness, no new life, and no hope. But because he did, we have all of these in full. Hallelujah, what a Savior!