Is it permissible to access one's fiancé's Facebook account without his knowledge to verify his religious commitment and character, or is that considered spying?

Espionage is forbidden unless it is to prevent an evil when suspicion arises. However, accessing a Facebook page is not considered espionage, because these pages are accessible to readers and are not secret. Therefore, there is no harm in accessing the suitor's account to learn about his morals and religiosity.