Human agency, then, cannot be of itself effectual. It is the _Lord_ who opens the ear, the eye, the conscience, the understanding, and the _heart_. The weapons of that spiritual warfare, in which Christian ministers are engaged, can alone "pull down strong holds, cast down imaginations, and every high thing that exalteth itself against the knowledge of God," and "bring into captivity every thought to the obedience of Christ," being "mighty _through God_." What would the weapon accomplish, if the hand of Almighty power were not to grasp and wield it? The experience of modern preachers, no doubt, resembles that of their apostolic predecessors in the same field of holy labour. When stout-hearted sinners have been attacked by all the force of argument, all the power of eloquence, all the fire of zeal, all the holy violence of appeal, all the tenderness of tears, and all the terrors of denunciation--and when it might have been expected that a heart of marble thus smitten must yield and break, and yet no emotion, at least no repentance, no relinquishment of sin, and no obedience to Christ has resulted--how often have they retired exclaiming, "_O the impotence of human instrumentality!_" But when returning to their work, desponding or deeply apprehensive, "going forth weeping, bearing precious seed," they have at length seen the rebel struck, and in a moment abashed, humbled, penitent--melted at a word--his prejudices dashed to the ground, like Lucifer from heaven--his heart opened, like that of Lydia, and the bitter stream of his enmity turned into the sweetness of Christian love--They have paused--inquired--wondered--beheld the "_excellency_ of the power," which was "not of man, but of God;" and have retired exclaiming, "_O the omnipotence of divine grace!_"