There underlies it, this solemn thought, which Christian people, and especially some types of Christian doctrine, do need to have hammered into them over and over again, that we hold the blessed life itself, and all its blessings, only on condition of our own cooperation in keeping them; and that just as physical life dies, unless by reception of food we nourish and continue it, so a man that is in this condition of being justified by faith, and having peace with God, needs, in order to the permanence of that condition, to give his utmost effort and diligence. It will all go if he do not. All the old state will come back again if we are slothful and negligent. We cannot keep the treasure unless we guard it. And just because we have it, we need to put all our mind, the earnestness of our will, and the concentration of our efforts, into the specific work of retaining it. For, consider how manifold and strong are the forces which are always working against our continual possession of this justification by faith, and consequent peace with God. There are all the ordinary cares and duties and avocations and fortunes of our daily life, which, indeed, may be so hallowed in their motives and in their activities, as that they may be turned into helps instead of hindrances, but which require a great deal of diligence and effort in order that they should not work like grains of dust that come between the parts of some nicely-fitting engine, and so cause friction and disaster. There are all the daily tasks that tempt us to forget the things that we only know by faith, and to be absorbed in the things that we can touch and taste and handle. If a man is upon an inclined plane, unless he is straining his muscles to go upwards, gravitation will make short work of him, and bring him down. And unless Christian men grip hard and continually that sense of having fellowship and peace with God, as sure as they are living they will lose the clearness of that consciousness, and the calm that comes from it. For we cannot go into the world and do the work that is laid upon us all without there being possible hostility to the Christian life in everything that we meet. Thank God there is possible help, too, and whether our daily calling is an enemy or a friend to our religion depends upon the earnestness and continuousness of our own efforts. But there is a worse force than these external distractions working to draw us away, one that we carry within, in our own vacillating wills and wayward hearts and treacherous affections and passions that usually lie dormant, but wake up sometimes at the most inopportune periods. Unless we keep a very tight hand upon ourselves, certainly these will rob us of this consciousness of being justified by faith which brings with it peace with God that passes understanding.