II.  And now note, again, how we come to this certitude.

My text is very significantly followed by a ‘for,’ which gives the reason of the knowledge in a very remarkable manner.  ’We know, ... for in this we groan, earnestly desiring to be clothed upon with our house, which is from heaven.’  Now that singular collocation of ideas may be set forth thus—­whatever longing there is in a Christian, God-inspired soul, that longing is a prophecy of its own fulfilment.  We know that there is a house, because of the yearning, which is deepest and strongest when we are nearest God, and likest what He would have us to be—­the yearning to be ’clothed upon with our house which is from heaven.’  That is a truth that goes a long way; though to enlarge on it is irrelevant to our present purpose.  It has its limitations, as is obvious from the context, in which are human elements which are not destined to be gratified, mingled with the yearning, which is of God, and which is destined to be satisfied.  But this at least we may firmly hold by, that just because God will not put men to confusion intellectually, and does not let them entertain uncherished—­still less Himself foster and excite—­longings which He does not mean to gratify, a Christian yearning for immortality is, to the man who feels it, a declaration that immortality is sure for him.  ’Delight thyself in the Lord, and He shall give thee the desires of thine heart.’  Whatsoever, in touching Him, we do deeply long for may have blended with it human elements, which will be dispersed unsatisfied, but the substance of it is a prophecy of its own fulfilment.  And as surely as the stork in the heavens, flying southward, will reach the sunny lands which draw it from the grim northern winter, so surely may a man say, ’I know that I have a house in heaven, because I long for it, and shrink from being found naked.’

Of course such longing, such aspiration and revulsion are no proofs of a fact except there be some fact which changes them, from mere vague desires, and makes these solid certainties.  And such a fact we have in that which is the only proof that the world has received, of the persistence of life through death and the continuance of personal identity unchanged by the grave, and that is the Resurrection of Jesus Christ from the dead.  Our faith in immortality does not depend merely on our own subjective desires and longings, but these desires and longings are quickened, confirmed, and certified by this great fact that Jesus Christ has risen from the dead; and therefore we know that the yearnings in us are not in vain.  So we come to this certitude, first, by reason of his experience; and, second, by reason of the longings which that experience fosters if it does not kindle, within our hearts.