Jamieson, Fausset and Brown on Genesis 1:26

26. The last stage in the progress of creation being now reached--God said, Let us make man--words which show the peculiar importance of the work to be done, the formation of a creature, who was to be God's representative, clothed with authority and rule as visible head and monarch of the world. In our image, after our likeness--This was a peculiar distinction, the value attached to which appears in the words being twice mentioned. And in what did this image of God consist? Not in the erect form or features of man, not in his intellect, for the devil and his angels are, in this respect, far superior; not in his immortality, for he has not, like God, a past as well as a future eternity of being; but in the moral dispositions of his soul, commonly called original righteousness (Ec 7:29). As the new creation is only a restoration of this image, the history of the one throws light on the other; and we are informed that it is renewed after the image of God in knowledge, righteousness, and true holiness (Col 3:10; Ep 4:24).