I. (1) Heaven is not the only domain of God's vast property. All here on earth belongs to Him as well. If all belongs to God, then comes in the liability to commit robbery against Him. For, it may be, that there shall be no general habitual sense and acknowledgment of His sovereign claims; no feeling that all does so belong. This is the comprehensive spirit and principle of the wrong toward Him, and will go into many special forms; this state of mind is a general refusal to acknowledge His law. (2) Coming to a more particular account of what may justly be called "robbing God," we may say that it is so, for anything to be suffered to have a stronger power over us than His will, so that that shall obtain from us what His will obtains not; whether it be our own inclinations or the opinions of men or the spirit, customs, example of the world.
II. A few plain particulars should be specified of what we cannot withhold from God without this guilt. (1) One plainly at first sight is, a very considerable proportion of thought concerning Him. (2) Fear, of the deepest, most solemn kind, is due to God. (3) Will a man refuse the gentler affections love, gratitude, humble reliance? These affections are to be given to go out to something. And are they just to go out to a few inferior objects close around us, and stop there, quite absorbed? Is it to the perfect excellence, the supreme goodness, the transcendent beauty, that the soul of man is to be indifferent and insensible? (4) Each and every precept of God's law tells of something we may refuse Him, namely, obedience; and a temptation stands close by each.
III. It is not for His own sake (in any sense intelligible to us) that God requires our homage, service, and obedience. It is for our sake; because all the things He requires will be for our good, here or hereafter, not only because He will so, but by the nature of the case. To be conformed to the will of God, to be delighted in performing services to Him, to be animated with the love of holiness and all that is good, and hatred of sin this would be to be happy (in heaven itself), and therefore required. In robbing God men iniquitously and fatally rob themselves.
J. Foster, Lectures,2nd series, p. 339.
References: Malachi 3:8. W. Baird, The Hallowing of our Common Life,p. 22.Malachi 3:8-18. Preacher's Monthly,vol. ii., p. 293.