The D&D 5e spell Commune is a Cleric spell that contacts the Cleric’s chosen divine proxy and asks them three ‘yes or no’ questions. It is a ritual spell, so a Warlock with Book of Shadows or anyone with the Ritual Caster feat really can learn and cast the spell.
Let’s say an atheist wizard uses the Ritual Caster feat to learn Commune (gaining Ritual Caster does not require belief in any pantheon) and then casts it (which can be done through an arcane focus). Who would she encounter? (If it helps, the Wizard belongs to the School of Divination.)