_In returning and rest shall ye be saved; in quietness and in confidence is your strength._ How divine Isaiah's message is, may be proved by the length of time mankind is taking to learn it. The remarkable thing is, that he staked so lofty a principle, and the pure religion of which it was the temper, upon a political result, that he staked them upon, and vindicated them by, a purely local and material success--the relief of Jerusalem from the infidel. Centuries passed, and Christ came. He did not--for even He could not--preach a more spiritual religion than that which He had committed to His greatest forerunner, but He released this religion, and the temper of faith which Isaiah had so divinely expressed, from the local associations and merely national victories, with which even Isaiah had been forced to identify them. The destruction of Jerusalem by the heathen formed a large part of Christ's prediction of the immediate future; and He comforted the remnant of faith with these words, to some of which Isaiah's lips had first given their meaning: _Ye shall neither in this mountain nor yet in Jerusalem worship the Father. God is a Spirit, and they that worship Him must worship Him in spirit and in truth._ Again centuries passed--no less than eighteen from Isaiah--and we find Christendom, though Christ had come between, returning to Isaiah's superseded problem, and, while reviving its material conditions, unable to apply to them the prophet's spiritual temper. The Christianity of the Crusades fell back upon Isaiah's position without his spirit. Like him, it staked the credit of religion upon the relief of the holy city from the grasp of the infidel; but, in ghastly contrast to that pure faith and serene confidence with which a single Jew maintained the inviolateness of Mount Zion in the face of Assyria, with what pride and fraud, with what blood and cruelty, with what impious invention of miracle and parody of Divine testimony, did countless armies of Christendom, excited by their most fervent prophets and blessed by their high-priest, attempt in vain the recovery of Jerusalem from the Saracen! The Crusades are a gigantic proof of how easy it is to adopt the external forms of heroic ages, how difficult to repeat their inward temper. We could not have more impressive witness borne to the fact that humanity--though obedient to the orthodox Church, though led by the strongest spirits of the age, though hallowed by the presence of its greatest saints, though enduring all trials, though exhibiting an unrivalled power of self-sacrifice and enthusiasm, though beautified by courtesy and chivalry, and though doing and suffering all for Christ's sake--may yet fail to understand the old precept that _in returning and rest men are saved, in quietness and in confidence is their strength_. Nothing could more emphatically prove the loftiness of Isaiah's teaching than this failure of Christendom even to come within sight of it.