Problem with function if(is_user_logged_in())…I think

Hi. I want that all my posts, pages and everything on my website be visible even to unregistered users. I think this should be the default setting, but for me it isn’t. If I access certain articles on my homepage, they look different from how they look when I’m logged in. What should I do to make all my website look the same for both unregistered and registered users?