John Calvin on John 8:40

40. But now you seek to kill me. He proves from the effect, that they are not the children of God, as they boasted, because they oppose God. And, indeed, is there any thing in Abraham that is more highly commended than the obedience of faith? “Et de faict, y a-il chose qu’on puisse plustost louer en Abraham?” This then is the mark of distinction, whenever we are required to distinguish between his children and strangers; for empty titles, whatever estimation they may procure before the world, are of no account with God. Christ therefore concludes again, that they are the children of the devil, because they hate with deadly hatred “Ils haissent de haine mortelle.” true and sound doctrine.