When we think of these weeks, it is reasonable to believe that such observance, so universal, so long continued, must have satisfied some deep need of the heart, especially as it is not based on any particular dogma. And this incident in the Saviour's life, and these emphatic words of His, may help us to a clearer understanding of the value of such times. They declare to us the principle of the spiritual harvest, that, in the spiritual life as in all else, we reap as we sow. They are intended to convey to us this plain lesson, that if any of us give little thought, attention, or effort to that side of our life which we speak of as the spiritual, if there is in our daily habit and practice little real prayer or self-denial, or devotion, little communing with God, little endeavour to live in the spirit of Christ, and if, this being so, we find ourselves weak or vacillating in our struggle against sin or evil, whether in our own life or in society, there is nothing surprising in such a result. It is in our religious life just as in everything else--spiritual carelessness or neglect must mean spiritual weakness. In all other matters we look for results in some proportion to our efforts. As we sow we expect to reap. Here, for instance, in your daily life, if you wish to excel in any particular game or pursuit, you practise it with diligence. You know that, without such practice or concentration of effort upon it, any expectation of excellence is simply foolish. In your school work you recognise the same conditions. Intellectual growth may seem sometimes to come slowly, in spite of all your efforts; but it comes with certainty if you persevere, and it is equally certain that it hardly ever comes at all to those who use no effort. If, then, you look for progress or distinction, you know that you must fix your thoughts upon your work, and practise industry, and, above all, that you must cultivate a love of learning, so that your mind lingers over it with some sense of enjoyment. You do not expect a harvest where you have not sown. And it is just this same law which you recognise and accept in other matters that our Lord is here declaring to us as the law of spiritual power. Do we desire to cast any evil influence or any weakness out of our life? Do we ask despairingly how it is that we have not been able to cast it out? Our Lord's answer comes to us in these emphatic words--"This kind can come forth by nothing, but by prayer." In other words, if we really desire that our soul shall be cleansed and strengthened, we must surrender it to Him in prayer and self-denial, in spiritual exercises and communion, that He may cure it of its sin or its weakness, and inspire us with new life.