John Calvin on 1 Corinthians 5:12

12. For what have I to do to judge them that are without? There is nothing to hinder us from judging these also — nay more, even devils themselves are not exempt from the judgment of the word which is committed to us. But Paul is speaking here of the jurisdiction that belongs peculiarly to the Church. “The Lord has furnished us with this power, that we may exercise it upon those who belong to his household. For this chastisement is a part of discipline which is confined to the Church, and does not extend to strangers. We do not therefore pronounce upon them their condemnation, because the Lord has not subjected them to our cognizance and jurisdiction, in so far as that chastisement and censure are concerned. We are, therefore, constrained to leave them to the judgment of God.” It is in this sense that Paul says, that God will judge them, because he allows them to wander about “Et courir a trauers champs;” — “And run across the fields.” unbridled like wild beasts, because there is no one that can restrain their wantonness.