Not only in the sphere of politics, but in that of religion also, were they constantly appearing as critics and censors. The tendency of religion to become merely ritual, to divorce itself from righteousness, is inveterate. Against this tendency the prophets were the constant witnesses. The religious "machine" is always in the same danger of becoming corrupt and mischievous as is the political "machine;" the man with the sledge-hammer who will smash it and fling it into the junk-pile has a work to do in every generation. This was the work of the Hebrew prophets. "I desired mercy, and not sacrifice," cries Hosea, speaking for Jehovah. "I hate, I despise your feast days," says Amos, "and I will not smell in your solemn assemblies,...but let judgment run down as waters, and righteousness as a mighty stream." "Your new moons and your appointed feasts my soul hateth," proclaims Isaiah; "they are a trouble unto me; I am weary to bear them. Wash ye, make you clean; cease to do evil; learn to do well. Is not this the fast that I have chosen, to loose the bands of wickedness, to undo the heavy burden, and to let the oppressed go free?" This is, then, the chief function of the Hebrew prophet; he is the expounder of the righteous will of God, not mainly with respect to future events, but with respect to present transgressions and present obligations of kings and priests and people. And yet it would be an error to overlook or disparage his dealings with the future. As a teacher of righteousness he saw that present disobedience would bring future retribution, and he pointed it out with the utmost fidelity. Any man who carefully studies the laws of God can make some predictions with great confidence. He knows that certain courses of conduct will be followed by certain consequences. Some of the predictions of the Hebrew prophets were of this nature. Yet predictions of this nature were always conditional. The condition was not always expressed, but it was always understood. The threatening of destruction to the disobedient was withdrawn when the disobedient turned from their evil ways. The predictions of the prophets were not always fulfilled for this good reason. The rule is explicitly laid down by the Prophet Jeremiah: "At what instant I shall speak concerning a nation...to destroy it; if that nation...turn from their evil, I will repent of the evil that I thought to do unto them. And at what instant I shall speak concerning a nation...to build and to plant it; if it do evil in my sight, that it obey not my voice, then I will repent of the good wherewith I said I would benefit them." [Footnote: Jeremiah xviii. 7-9.]