From the Confessions: The Defense of the Augsburg Confession
Concerning Original Sin
Irenaeus and Ambrose interpreted the image of God in that way, the latter saying many things to this effect, but especially: “That soul is not in the image of God in whom God is not always present.” Paul shows in the Epistles that the image of God is the knowledge of God, righteousness, and truth (Eph 5:9; Col 3:10). Peter Lombard was not afraid to state that original righteousness is the very likeness of God implanted in people by God. These opinions of the ancients that we reference do not disagree in any way with Augustine's interpretation of the image of God.
So when the ancient definition is that sin is the lack of righteousness, it not only denies obedience of the low human powers (that people are corrupt in body and the basest and lowest faculties), but also denies the knowledge of God, confidence in God, the fear and love of God—or certainly the power to produce these affections (any light in the heart that creates a love and desire for such concerns). Even the theologians teach in their schools that these are not produced without certain gifts and the assistance of grace. In order that the matter may be understood, we call these gifts the knowledge of God, and fear and confidence in God.
It is clear from these facts that the ancient definition says precisely the same thing that we state about human nature, by denying fear and confidence toward God—not only the acts, but also the gifts and power to produce these acts (not only that we are unable to do or achieve any perfectly good work but that we do not have a good heart toward God, one that truly loves God).
Pulling It Together: Some background may be helpful. The Church Fathers were those whose theological writings were most influential in the early Church. Irenaeus (early first century) and Ambrose (late fourth century) were two of those fathers of the Church. The former was a second-generation student of the Apostle John, having learned from John's disciple, Polycarp. Irenaeus was a bishop and respected apologist (defender of the faith), writing at length against heresies, especially against Gnosticism Ambrose was also a bishop of the Church. His writings refuted Arianism and influenced Augustine. It is no wonder that Augustine's interpretation agreed with Irenaeus and Ambrose, particularly the latter.
Not only did these two Church Fathers consider the image of God to be his nature, even Lombard, who was one of the scholastics whom the Lutherans cared little for (and this is putting it mildly), clearly stated the same. The ancient teaching of the Church about the “image” or “likeness of God” is certain. Its definition of sin is just as definite. Sin is a lack of righteousness and even the desire or ability to achieve anything perfectly good with regard to God. Therefore, the image of God that was in the creation of Adam and Eve was the “original righteousness” of a fearing, loving, and trusting knowledge of God. These, along with the power to live a life that reflects God's image, were stamped upon their being. That likeness of God, because of Adam's sin, is no longer part of human nature.
This is why Paul teaches us to put off the old self, the person created in Adam's image. We are charged with putting on the new self, the one recreated, reborn in God's image. By his grace, we have been given the likeness or nature of God and therefore, are now enabled to desire and to do good toward God and one another because of the love of God that has been revived in us through faith in Jesus Christ.
Prayer: Enable whatever I do today, Father, in word or deed, to be done in the name of my Lord Jesus Christ. Amen.