Most of us don’t believe in ghosts or zombies ... unless of course we mean memories from our past that haunt us or things we did in the past we thought were dead and buried that come back to life and stalk us. Those are reality.
We believe in those and we try to defeat them by avoiding, escaping, re-burying or fighting but nothing has any lasting success.
So what can deal with the guilt and shame from our past so we don’t fear it anymore? Can anything wash away my sin? The Good News answer to that question is - the Gospel - nothing but the blood of Jesus can.