The quiet heart will be able to fling its whole strength into its work. And that is what troubled hearts never can do, for half their energy is taken up in steadying or quieting themselves, or is dissipated in going after a hundred other things. But when we are wholly engaged in quiet fellowship with Jesus Christ we have the whole of our energies at our command, and can fling ourselves wholly into our work for Him. The steam-engine is said to be a very imperfect machine which wastes more power than it utilises. That is true of a great many Christian people; they have the power, but they are so far away from that deep sense of tranquillity with God, of which my text speaks, that they waste much of the power that they have. And if we are to have for our motto 'Always Ready.' as an old Scottish family has, the only way to secure that is by having 'our feet shod with the preparedness' that comes from the Gospel that brings us peace. Brethren, duty that is done reluctantly, with hesitation, is not done. We must fling ourselves into the work gladly and be always 'ready for all Thy perfect will.' There was an English commander, who died some years ago, who was sent for to the Horse Guards one day and asked, 'How long will it take for you to be ready to go to Scinde?' 'Half an hour,' said he; and in three-quarters he was in the train, on his road to reconquer a kingdom. That is how we ought to be; but we never shall be, unless we live habitually in tranquil communion with God, and in the full faith that we are at peace with Him through the blood of His Son. A quiet heart makes us ready for duty. III. Again, the Gospel of peace prepares us for combat. In ancient warfare battles were lost or won very largely according to the weight of the masses of men that were hurled against each other; and the heavier men, with the firmer footing, were likely to be the victors. Our modern scientific way of fighting is different from that. But in the old time the one thing needful was that a man should stand firm and resist the shock of the enemies as they rushed upon him. Unless our footing is good we shall be tumbled over by the onset of some unexpected antagonist. And for good footing there are two things necessary. One is a good, solid piece of ground to stand on, that is not slippery nor muddy, and the other is a good, strong pair of soldier's boots, that will take hold on the ground and help the wearer to steady himself. Christ has set our feet on the rock, and so the first requisite is secured. If we, for our part, will keep near to that Gospel which brings peace into our hearts, the peace that it brings will make us able to stand and bear unmoved any force that may be hurled against us. If we are to be 'steadfast, unmovable,' we can only be so when our feet are shod with the preparedness of the Gospel of peace.