God tells us that He will look upon what is done in charity to our neighbors as done unto Him and what is denied unto them as denied unto Him: “He that hath pity on the poor lendeth to the LORD” (Prov. 19:17). God has been pleased to make our needy neighbors His receivers. He in His infinite mercy has so interested Himself in their case that He looks upon what is given in charity to them as given to Himself; and when we deny them what their circumstances require of us, He looks upon it that we rob Him of His right. Christ teaches us that we are to look upon our fellow Christians in this case as Himself, and that our giving or withholding will be taken as if we so behaved ourselves toward Him. Christ says to the righteous on His right hand, who has supplied the wants of the needy, “Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me” (Matt. 25:40). In like manner He says to the wicked who did not show mercy to the poor, “Inasmuch as ye did it not to one of the least of these, ye did it not to me” (Matt. 25:45). Now what stronger enforcement of this duty can be conceived? Is it possible that Jesus Christ looks upon our kind and bountiful, or unkind and uncharitable, treatment of our needy neighbors as such a treatment of Himself?

From “Christian Charity,” p. 166