Why does the_content not work like others for a set post id?

There are many globals that are being set in a loop, not only $post, and you need to set all of them to get exactly the same behavior. To get this it is not enough to set $post but you also need to use setup_postdata

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)