Will they go to hell?

Unfortunately, you can't just be a Christian by saying you're a Christian. It would be nice if it were that simple. You can't "do" your way into heaven. You can't "say" your way into heaven. You can only "be" your way into heaven. Part of being a Christian is being forgiven of your sins and not sinning any further. In your scenario, they do not sound like they've repented and truly given themselves to Christ. Lots of "good" people wind up in heaven. Being "good" isn't enough.