[Tyler Henry1]

So I just got my Lumia 925 and I distinctively remember adding a facebook account to sync with my phone, and for some reason it doesn't show up under settings. Because of this, I can't view my Facebook messages from the messenger app like I could on my other windows phone.

[TechFreak1]

I presume you checked email + accounts in the settings?

Also what build version is your phone running on? (you can check by going to "about windows phone" in settings, if you want post a screen shot, make sure you crop out your IMEI, MAC Address etc)

As on Windows Phone 8.1 social media syncing has been decoupled from the O/S in favour of the Social Extensibility Framework.
Sharing is caring – How the Social Extensibility framework for Windows Phone 8.1 will make things better | Windows Phone Central.

As MS ran in to an issue where for example Facebook would introduce new features and it would take an O/S level update to implement those features. Similarly if there were backend changes, it would break the integrated version of Facebook.