What is original sin? The correct answer is, that it is immoderate
[unchecked] concupiscence. The correct answer is also, that it is
want of the righteousness that is due. And in one of these replies
the other is included. The same is the opinion of Hugo, when he says
that original sin is ignorance in the mind and concupiscence in the
flesh. For he thereby indicates that when we are born, we bring with
us ignorance of God unbelief, distrust, contempt, and hatred of God.
For when he mentions ignorance, he includes these. And these
opinions [even of the most recent teachers] also agree with Scripture.
For Paul sometimes expressly calls it a defect [a lack of divine
light], as 1 Cor. 2, 14: The natural man receiveth not the things of
the Spirit of God. In another place, Rom. 7, 5, he calls it
concupiscence working in our members to bring forth fruit unto death.
We could cite more passages relating to both parts, but in regard to
a manifest fact there is no need of testimonies. And the intelligent
reader will readily be able to decide that to be without the fear of
God and without faith are more than actual guilt. For they are
abiding defects in our unrenewed nature.

In reference to original sin we therefore hold nothing differing
either from Scripture or from the Church catholic, but cleanse from
corruptions and restore to light most important declarations of
Scripture and of the Fathers, that had been covered over by the
sophistical controversies of modern theologians. For it is manifest
from the subject itself that modern theologians have not noticed what
the Fathers meant when they spake of defect [lack of original
righteousness]. But the knowledge of original sin is necessary. For
the magnitude of the grace of Christ cannot be understood [no one can
heartily long and have a desire for Christ for the inexpressibly
great treasure of divine favor and grace which the Gospel offers],