“And God said, Let us make man in our image, after our likeness.” (Gn 1:26)
Origen (185-253), who lectured at the catechetical school in Alexandria, taught that man received the dignity of the image of God at his creation, but that each person acquires the perfection of the likeness of God through his personal efforts, aided by the grace of God. In his De principiis (First Principles), Origen distinguishes between image and likeness. Here is what he says in Book Three, at the beginning of Chapter Six:
According to philosophers, he says, the highest good which a rational nature seeks is “to become as like to God as possible.” But he adds: “This definition I regard not so much as a discovery of theirs, as a view derived from holy Scripture. For this is pointed out by Moses, before all other philosophers, when he describes the first creation of man in these words: ‘And God said, Let Us make man in Our own image, and after Our likeness’ (Gn 1:26); and then he adds the words: ‘So God created man in His own image: in the image of God created He him; male and female created He them, and He blessed them’ (Gn 1:27-28).”
“Now the expression, ‘In the image of God created He him,’ without any mention of the word ‘likeness,’ conveys no other meaning than this, that man received the dignity of God’s image at his first creation; but that the perfection of his likeness has been reserved for the consummation,—namely, that he might acquire it for himself by the exercise of his own diligence in the imitation of God, the possibility of attaining to perfection being granted him at the beginning through the dignity of the divine image, and the perfect realization of the divine likeness being reached in the end by the fulfilment of the (necessary) works.”
“Now, that such is the case, the Apostle John points out more clearly and unmistakably, when he makes this declaration: ‘Little children, we do not yet know what we shall be; but if a revelation be made to us from the Saviour, ye will say, without any doubt, we shall be like Him’ (1 Jn 3:2). By which expression he points out with the utmost certainty, that not only was the end of all things to be hoped for, which he says was still unknown to him, but also the likeness to God, which will be conferred in proportion to the completeness of our deserts.”
Quotations from Ante-Nicene Fathers, Vol. IV, ed. Alexander Roberts and James Donaldson (Edinburgh: T&T Clark, 1867).