We're waiting for the final restoration of creation whic Isaiah describes. While we wait, we don't know with certainty that our faith is not in vain. We can't know. We don't get to see God or our loved ones who have died so that we might believe in God and the resurrection. Rather, we believe in God and the resurrection and allow that belief to be real enough to change our lives, seeing joy, hope, peace, and love in the world.