When you take this oath at 3rd level, you gain the following two Channel Divinity options.

Aura of Truth At 7th level, you emmanate an aura of guidance and intuition. You and friendly creatures within 10 feet of you have advantage on Insight and Investigation checks. Affected creatures can sense if there is an illusion within 30 feet of them, but not its nature or specific location.

Imperative of Truth At 15th level, your conviction can force the truth out of others and punish those who would deceive. As a bonus action, you can compel a creature you can see to answer one question of 6 words or fewer. The target must succeed on a Wisdom saving throw or they are forced to answer the question. The target understands the question even if they do not share a language with you. If the target lies, they take 2d8 psychic damage. You are aware if the creature takes this damage, but not if they succeeded on the saving throw and cannot ask creature the same question twice.