For the time is come that judgment must begin at the house of God: and if it first begin at us, what shall the end be of them that obey not the gospel of God? Judgment must begin at the house of God - Our Lord had predicted that, previously to the destruction of Jerusalem, his own followers would have to endure various calamities; see Matthew 24:9, Matthew 24:21, Matthew 24:22; Mark 13:12, Mark 13:13; John 16:2, etc. Here his true disciples are called the house or family of God. That the converted Jews suffered much from their own brethren, the zealots, or factions into which the Jews were at that time divided, needs little proof; and some interpreters think that this was in conformity to the purpose of God, (Matthew 23:35 : That on you may come all the righteous blood shed from the foundation of the world), "that the Jewish Christians were to be involved in the general punishment; and that it was proper to begin at them as a part of the devoted Jewish nation, notwithstanding they were now become the house of God, because the justice of God would thereby be more illustriously displayed." See Macknight. But probably the word κριμα, which we here translate judgment, may mean no more than affliction and distress; for it was a Jewish maxim that, when God was about to pour down some general judgment, he began with afflicting his own people in order to correct and amend them, that they might be prepared for the overflowing scourge. In Bava Kama, fol. 60, 1, we have the same sentiment, and in nearly the same words, as in Peter, viz.: "God never punishes the world but because of the wicked, but he always begins with the righteous first. The destroyer makes no difference between the just and the unjust, only he begins first with the righteous." See Ezekiel 9:1-7, where God orders the destroyer to slay both old and young in the city: But, said he, begin at my sanctuary.
And if it first begin at us - Jews, who have repented, and believed on the Son of God; what shall the end be of them - the Jews who continue impenitent, and obey not the Gospel of God? Here is the plainest reference to the above Jewish maxim; and this, it appears, was founded upon the text which St. Peter immediately quotes.