R.C. Sproul:

“Other theologians argue that image and likeness are really synonyms in this verse, so we cannot make a neat distinction between the two. They—including most traditional Protestant theologians—explain the situation this way: There is a wider sense in which man is the image of God (imago essentialis), and also a narrow or particular sense (imago conformitas). In the wider sense, man simply is the image of God, and since that is what man is by definition, it cannot be changed or lost. As long as man is man, he is the image of God.

“In the narrow sense, however, man images God’s holiness and righteousness. Man, therefore, stopped imaging God at the Fall. He lost his conformity to God’s image. We are still the image of God, but we are distorting that image. If other people look at us to see what God is like, they will get the wrong idea, because we image Him imperfectly. Only in Jesus Christ do we see a man who is the perfect image of God in both senses.” – R.C. Sproul, Tabletalk Magazine, August 1990: Parables: Kernels of Truth, 40.

Turretin on the dignity of man:

"Fifth, the dignity of man himself [Hominis ipsius dignitas] demands the same thing [that the promise given to Adam was not only of a happy life to be continued in paradise, but of a heavenly and eternal life]. Since his noblest part is spirit (even of heavenly origin) touched with a vehement desire of heavenly goods (by which alone its infinite appetite for the highest good can be satisfied), he could not obtain on earth his full felicity, but must be gifted with it at length in heaven where he can enjoy the fullest and most perfect communion with God, in whom his highest good resides. For although on earth he could in some measure give himself to be enjoyed, it is certain that the immediate and absolute fruition of God is not to be sought apart from the beatific vision which can be looked for only in heaven." IET 8.6.8

"Although the body of Adam was in origin earthy (and as composed, so also resolvable, through the indisposition of matter), yet it could have been immortal through the dignity of original righteousness [originalis justitiae dignitatem] and the power of God’s special grace." IET 5.12.9

"We maintain that the loss of the divine image (or of original righteousness) followed the fall of Adam doubly—both meritoriously and morally (on account of the divine ordination) and efficiently and really (on account of the heaviness of that sin)."

"By the divine image, we do not understand generally whatever gifts upright man received from God (spoken of in Gen. 1:26, 27) or specially certain remains of it existing in the mind and heart of man after the fall (in which sense we understand Gen. 9:6 and Jam. 3:9). Rather we understand it strictly of the principal part of that image which consisted of holiness and wisdom."

Jonathan Edwards:

“Before I dismiss this head of the degenerating of experiences, I would mention one thing more that tends to it; and that is, persons aiming in their experience to go beyond the rule of God's Word, i.e. aiming at that which is indeed, in some respect, beyond the rule. Thus some persons have endeavoured utterly to root out and abolish all natural affection, or any special affection or respect to their near relations, under a notion that no other love ought to be allowed but spiritual love, and all that other love is to be abolished as carnal, and that it becomes Christians to love none upon the account of any thing else but the image of God; and that therefore love should go out to one and another only in that proportion in which the image of God is seen in them. They might as well argue that a man ought utterly to disallow of, and endeavor...