The connection with the previous part is twofold.
The warning against hypocritical fastings and formalism leads to the warning against worldly-mindedness and avarice. For what worldly-mindedness is greater than that which prostitutes even religious acts to worldly advantage, and is laying up treasure of men's good opinion on earth even while it shams to be praying to God? And there is a close connection which the history of every age has illustrated between formal religious profession and the love of money, which is the vice of the Church. Again, the promise of rewarding openly naturally leads on to the positive exhortation to make that reward our great object.
The connection with what follows is remarkable. The injunction and prohibition of the text refer to two species of the same genus, one the vice of avarice, the other the vice of anxiety.
I. The Two Treasures.
These are -- on earth, all things which a man can possess; -- in heaven, primarily God Himself, the reward which has been spoken of in previous verses, viz. God's love and approbation, a holy character, and all those spiritual and personal graces, beauties, perfections and joys which come to the good man from above.
This command and prohibition require of Christ's disciples --
1. A rectification of their judgment as to what is the true good of man.
(a) Sense and flesh tend to make us think the visible and material the best.
(b) Our peculiar position here in a great commercial centre powerfully reinforces this tendency.
(c) The prevailing current of this age is all in the same direction. The growth of luxury, the increase of wealth, and set of thought, threaten us with a period when not only religious thought will fail, but when all faith, enthusiasm, all poetry and philosophy, the very conception of God and duty, all idealism, all that is unseen, will be scouted among men. Naturalism does not fulfil its own boast of dealing with facts; there are more facts than can be seen. So the first thing is to settle it in our minds, in opposition to our own selves and to prevailing tendencies, that truth is better than money, that pure affections and moderate desires and a heart set on God are richer wealth than all external possessions.
2. Desire that follows the corrected judgment. It is one thing to know all this, another to wrench our wishes loose from earth.
3. A practical life that obeys the impulse of the desire. Christ's command and prohibition here do not refer only to a certain course of action, but to a certain motive and purpose in action, and to actions drawn from these. If we obey Christ we shall lead lives obviously different from those which are based upon an estimate which we are to reject; but the main thing is to live and work with an eye to the eternal, not the temporal, results of our doings. We are to administer our lives as God does His providence, using the temporal only as means to an end, the eternal. We are to live to be God-like, to love God, and be loved by Him.
There is here the idea of which we are somewhat too much afraid, that our life on earth adds to the rewards of blessedness in heaven. The idea of reward is emphatically and often inculcated in Scripture, however much a mistaken jealousy for 'the doctrines of Grace' may be chary of it. We need only recall such words as 'They shall walk with Me in white, for they are worthy'; or, 'Laying up in store for themselves a good foundation'; or, 'Thou shalt have treasure in heaven.' If people would only think of heaven less carnally, and would regard it as the perfection of holiness, there would be no difficulty in the notion of reward. Men get there what they have made themselves fit for here. 'Their works do follow them.'
II. The foes of the earthly, which are powerless against the heavenly.
The imagery implies a comparatively simple state of society and primitive treasures. Moths gnaw rich garments. Rust, or more properly corruption, would get into a man's barns and vineyards, hay-crops and fruits. Thieves would steal the hoard that he had laid by, for want of better investment. Or to generalise, corruption, the natural process of wearing away, natural enemies proper to each kind of possession, human agency which takes away all external possessions -- these multifarious agents co-operate to render impossible the permanent possession of any 'treasure on earth.'
On the other hand, what a man has laid up in heaven, and what he is partially here, have no tendency to grow old. Men never weary of God, never find Him failing, never exhaust truth, never drink the love of God to the dregs, never find purity palling upon the taste, 'Age cannot wither, nor custom stale, "their" infinite variety.'
'Treasure in heaven' has no enemies which destroy it. Every earthly possession has its own foes, every earthly joy has its own destructive opposite; but nothing touches this treasure in heaven.
It has nothing to fear from men. Nobody can take it out of a man's soul but himself. The inmost circle of our life is inviolable. It is incorruptible and undefiled and fadeth not away, for it all comes from the eternal God and our eternal union to Him. He is our portion for ever.
III. The madness of fastening the heart down to earth.
The heart must be in heaven in order to find its true home. It is unnatural, contrary to the constitution of the 'heart' that it should be fettered to earth.
If it is, it will be restless and unsatisfied.
If it is, it will be at the mercy of all these enemies.
If it is, what will happen when the man is no longer on earth? 'What shall it profit a man if he gain the whole world and lose his own soul?'