centos7 – Centos 7 Apache web server not using the new document root directory

I have installed apache web server on my Centos 7, and I have enabled mod_ssl for it. But when I try to change its default document root to a new one (for example /home/user/public_html), it shows me a 403 Forbidden page. I think maybe it’s because of the permissions on the directory, but I don’t know what to do with it and how to change it. What should I do now? Any help is really appreciated.