What was the business of the ancient prophet? Not merely to predict events. His chief work was to make men realise vividly the presence of God. Religions, in order to their permanence, require system. But religious systems, with their creeds, forms, and ceremonies, have an inevitable tendency to coldness and deadness. The prophet was sent to counteract this tendency. It was his mission to restore to great words their great meanings, to cause moral principles to reassert themselves as the lords of conscience and of will--in a word, to prophesy on the dry bones of a decaying religion until there came upon them flesh and sinew, and there passed into them the breath of spiritual life. Such a mission was that of Isaiah. In his time religion was in a state of petrifaction, nay, rather of putrefaction. From this fact his prophetic message takes its keynote. It begins with an invective that reminds us of John the Baptist. What was the condition of things that provoked his indignation? Not a lack of religious observances; there was a redundancy of them. That which caused a righteous anger to burn with him vehemently was their perversion of the sacrificial system to which they gloried, their dissociation of it from the moral law, to which God intended it to be only a supplement. It was given to teach men the hatefulness of sin, and the duty of consecration to God; but they separated it from the moral law, and allowed all its spiritual meaning to drop out of it. Instead of using it as a help to morality, they were making it the substitute for morality. Coming up red-handed from their murders, and reeking with their foul vices, they stood up before God, claiming His favour; for were they not sacrificing to Him, yea, in accordance with the regulations Himself had given? No wonder that a man with veracity in him and a love of righteousness should pour out upon such men and such offerings the whole wrath of his nature.