Of course, before we can love an unseen person and believe in his love, we must know about him by the ordinary means by which we learn about all persons outside the circle of our sight. So before the love which is thus the parent of deep, true knowledge, there must be the knowledge by study and credence of the record concerning Christ, which supplies the facts on which alone love can be nourished. The understanding has its part to play in leading the heart to love, and then the heart becomes the true teacher. He that loveth, knoweth God, for God is love. He that is rooted and grounded in love because Christ dwells in his heart, will be strengthened to know the love in which he is rooted. The Christ within us will know the love of Christ. We must first 'taste,' and then we shall 'see' that the Lord is good, as the Psalmist puts it with deep truth. First, the appropriation and feeding upon God, then the clear perception by the mind of the sweetness in the taste. First the enjoyment; then the reflection on the enjoyment. First the love; and then the consciousness of the love of Christ possessed and the love to Christ experienced. The heart must be grounded in love that the man may know the love which passeth knowledge. Then notice that there is also here another condition for this deep and blessed knowledge laid down in these words, 'That ye may be able to comprehend _with all saints_.' That is to say, our knowledge of the love of Jesus Christ depends largely on our sanctity. If we are pure we shall know. If we were wholly devoted to Him we should wholly know His love to us, and in the measure in which we are pure and holy we shall know it. This heart of ours is like a reflecting telescope, the least breath upon the mirror of which will cause all the starry sublimities that it should shadow forth to fade and become dim. The slightest moisture in the atmosphere, though it be quite imperceptible where we stand, will be dense enough to shut out the fair, shining, snowy summits that girdle the horizon and to leave nothing visible but the lowliness and commonplaceness of the prosaic plain. If you want to know the love of Christ, first of all, that love must purify your souls. But then you must keep your souls pure, assured of this, that only the single eye is full of light, and that they who are not 'saints' grope in the dark even at midday, and whilst drenched by the sunshine of His love, are unconscious of it altogether. And so we get that miserable and mysterious tragedy of men and women walking through life, as many of you are doing, in the very blaze and focus of Christ's love, and never beholding it nor knowing anything about it.