Page not found

Please see https://www.tennesseetemple.org If I am logged in as admin, I can click on Students and it displays that page. However, if I am logged in as anyone else, it gives me a 404 Page not Found error.At one time, I had clicked on the blocked box, hoping to hide it from users unless they are logged in. How can I set it so if a user isn’t logged in, it will display a message like, “You must be logged in to view this page.” and display the login fields?

Thank you.