They are "turncoats" (hafachpechanim), they are "runabouts." "sons without emun": You are sons without emunah (faith). You stood before Mount Sinai and said (Shemoth 24:7) "All that the L-rd spoke we will do and we will hear." I, too, said to you (Psalms 82:6) "You are angels." But since they said of the golden calf (Shemoth 32:4) "These are your gods, O Israel," I, too, said of you (Psalms, Ibid. 7) "but like men will you die."
I brought you into the land of your forefathers and I gave you the Temple. I said to you: You will never be exiled from it. But since you said (II Samuel 20:1) 'We have no part in David," I, likewise, said to you (Amos 7:17) "And Israel will be exiled from its land." R. Dostai says: Read it not ("sons) without emun; but "without 'Amen.'"
They did not want to answer "Amen" after the prophets when they blessed them. And thus is it written (Jeremiah 11:5) "in order to fulfill the oath that I swore to your forefathers to give them a land flowing with milk and honey, as this very day." And not one of them opened his mouth and answered Amen, until Jeremiah came and answered Amen, as it is written (Ibid.) "And I answered and said: 'Amen, O L-rd!'"