Anthony Hoekema on what it means for man to be made in the image of God:
Since Christ was totally without sin, in Christ we see the image of God in its perfection. As a skillful teacher uses visual aids to help his or her pupils understand what is being taught, so God the Father has given us in Jesus Christ a visual example of what the image of God is. There is no better way of seeing the image of God than to look at Jesus Christ. What we see and hear in Christ is what God intended for man.
If this is so, then the best way to learn what the image of God is is not to contrast man with animals, as has often been done, and then to fine the divine image to consist in those qualities, abilities, and gifts that man has in distinction from the animals. Rather, we must learn to know what the image of God is by looking at Jesus Christ. What must therefore be at the center of the image of God is not characteristics like the ability to reason or the ability to make decisions (important as such abilities may be for the proper functioning of the image of God), but rather that which was central in the life of Christ: love for God and love for man. If it is true that Christ perfectly images God, then the heart of the image of God must be love. For no man ever loved as Christ loved.
Created in God’s Image p. 22