Classes

Nope

There won't be any classes in Pax Dei, a direct quote from the developer puts it best:

What you will find in Pax Dei is NOT a predefined set of things that we have in our infinite designer wisdom decided would make a good tank. What you WILL find are skills, specializations, armour, weapons, accessories, enchantments, abilities and/or spells that may be useful for someone wanting to be the Tank.

But, what about the holy trinity?

Here's another direct quote from the developer:

The gameplay will support the "holy MMO trinity" - i.e. tank, healer, dps roles, but we're aiming to be a bit more flexible when it comes to selecting your playstyle, gear and strategies. Unlike in most MMOs, you don't pick a class and be locked to it but define your role with gear, spells and your playstyle etc instead which also allows exploring different playstyles and evolving your character over the years.