If I should vainly attempt to fashion my discourse after lofty models, I should this morning compare the human heart to the ancient city of Thebes, out of whose hundred gates multitudes of warriors were wont to march. As was the city such were her armies, as was her inward strength, such were they who came forth of her. I might then urge the necessity of keeping the heart, because it is the metropolis of our manhood, the citadel and armoury of our humanity. Let the chief fortress surrender to the enemy, and the occupation of the rest must be an easy task. Let the principal stronghold be possessed by evil, the whole land must be overrun thereby. Instead, however, of doing this, I shall attempt what possibly I may be able to perform, by a humble metaphor and a simple figure, which will be easily understood; I shall endeavour to set forth the wise man’s doctrine, that our life issues from the heart, and thus I shall labour to show the absolute necessity of keeping the heart with all diligence. You have seen the great reservoirs provided by our water companies, from which the water which is to supply hundreds of streets and thousands of houses comes. Now, the heart is just the reservoir of man, and our life is allowed to flow in its proper season. That life may flow through different pipes—the mouth, the hand, the eye; but still all the issues of hand, of eye, of lip, derive their source from the great fountain and central reservoir, the heart; and hence there is no difficulty in showing the great necessity that exists for keeping the reservoir, the heart, in a proper state and condition, since otherwise that which flows through the pipes must be tainted and corrupt.
For meditation: God is the only one who knows the natural wickedness of our hearts (Jeremiah 17:9), the only one who can renew them (Ezekiel 36:25-26) and the only one who can produce good from them (John 7:38-39).
Sermon no. 179 20 February (Preached 21 February 1858)