The edit_pages capability only allows a user to edit his own unpublished pages. It does neither allow to edit others pages (this would require the edit_others_pages capability) nor does it allow to publish or edit published pages (capabilities: publish_pages and edit_published_pages).
I’d strongly recommend having a look on this wonderful table: https://codex.wordpress.org/Roles_and_Capabilities#Capability_vs._Role_Table
listing up all avaliable native WordPress capabilities against the roles they belong to.