Witsius on the Image of God in Man

Witsius defines what the Image of God means in reference to Adam before the fall.

But if we take in the whole extent of the image of God, we say, it is made up of these three parts. 1st, Antecedently, that it consists in the spiritual and immortal nature of the soul, and in the faculties of understanding and will, 2dly, Formally and principally, in these enduments, or qualities of the soul, viz. righteousness, and holiness. 3dly, Consequentially, in the immortality of the whole man, and his dominion over the creatures. The first of these was, as one elegantly expresses it, as precious ground on which the image of God might be drawn and formed: the second, that very image itself, and resemblance of the divinity: the third, the lustre of that image widely spreading its glory; and as rays, not only adorning the soul, but the whole man, even his very body; and rendering him the lord and head of the world, and at the same time immortal, as being the friend and confederate of the eternal God.

(p. 57, Witsius, Vol. 1)(Book I, Chapter II, paragraph XI))