Let us make man in our image after our likeness; and let him have dominion over the fish of the sea, and over the birds of the air, and over the cattle, and over all the earth (Gen. 1:26).
From this it is clear that the Holy Trinity has placed its image in man so that in the whole life and walk of man pure divine holiness, righteousness, and goodness ought to appear and shine forth, just as divine love, power, and purity is found in the holy angels. In man God wished to have his joy and pleasure as in his children. Just as a father sees himself and rejoices in his child, so also God has his joy in men (Prov. 8:31). Although the Lord God has pleasure in all his works, yet he had a special joy in man, since in man his image shone forth in the highest innocence and clarity. There are three chief powers created in the human soul by God: understanding, will, and memory. These powers the Holy Trinity brings forth and protects, makes holy and illuminates, adorns and embellishes with its grace, works, and gifts.
An image is that in which one can see a similar likeness and form and there can be no image unless it is like that to which it is made as an image. No image can appear in a mirror unless it receive its likeness or a like form from something else, and the clearer the mirror, the purer the image shines forth. Thus the purer and cleaner the human soul, the clearer the image of God shines forth from it.
Johann Arndt