For the time has come for judgment to begin at the house of God. If it begins first with us, what will happen to those who don't obey the Gospel of God?
what will be the outcome …? If the people of God need purifying, then surely the judgment of those who do not obey the gospel will be much more severe (cf. vv. 3–5). Peter reinforces this point by quoting Proverbs 11:31 from the Septuagint. - ESVSB