Man is not in the image of God, according to his external bodily form and figure. The image of God in man consisted not in the what is seen, but in what is not seen; not in the conformation of those members, but rather in the spiritual faculties of the soul; or, most of all, in the holy endowments of those faculties (Ephesians 4:24): “That ye put on the new man, which after God is created in righteousness and true holiness.” The image which is restored by redeeming grace, was the image of God by original nature. The image of God cannot be in that part which is common to us with beasts, but rather in that wherein we excel all living creatures, in reason, understanding, and an immortal spirit. God expressly saith, that none “saw a similitude” of him (Deuteronomy 4:15-16); which had not been true, if man, in regard of his body, had been the image and similitude of God, for then a figure of God had been seen every day, as often as we saw a man or behold ourselves. Nor would the apostle’s argument stand good (Acts 17:29), “That the Godhead is not like to stone graven by art,” if we were not the offspring of God, and bore the stamp of his nature in our spirits rather than our bodies. . . The soul comes nearest the nature of God, as being a spiritual substance; yet considered singly, in regard of its spiritual substance; cannot well be said to be the image of God; a beast, because of its corporeity, may as well be called the image of man, for there is a great similitude between man and a brute, in the rank of bodies, than there can be between God and the highest angels in the rank of spirits. If it doth not consist in the substance of the soul, much less can it in any similitude of the body. 

The Existence and Attributes of God (Vol. 1) - Stephen Charnock