William Lincoln, “Sermons on Subjects Connected with the Second Advent of Our Lord Jesus Christ”, 1859
[Throughout] all eternity, wherever I meet David, I shall know full well, having been taught by God himself, that David was an egregious sinner as well as an exemplary saint. His sins, [indeed] the sins of every worthy mentioned in the Bible, are known wherever that Bible is read. It cannot be otherwise. For then would the great set-off to God's grace, the background of the picture, be withdrawn. Will not angels know we are sinners? And is not this more than half the truth for which we are contending? For is not the fact of being a sinner as solemn [a thing] as that we have been guilty of acts of transgression? (We are not sinners only because we sin, but we sin because we are sinners. How often is this lost sight of!)
Watchman Nee The Normal Christian Life, 1957
Those who so use it are in danger of arguing the wrong way round, for the teaching of (Romans 5:19) is not that we are sinners because we commit sins, but that we sin because we are sinners. We are sinners by constitution rather than by action.
R. C. Sproul
What Is Reformed Theology: Understanding the Basics, 1997
Jesus frequently described this condition with images drawn from nature. Just as a corrupt tree yields corrupt fruit, so sin flows out of a corrupt human nature. (Matthew 7:18, 15:19)
We are not sinners because we sin; we sin because we are sinners. Since the fall human nature has been corrupt. We are born with a sin nature. Our acts of sin flow out of this corrupted nature.
Everyone’s a Theologian: An Introduction to Systematic Theology
Sin is real. There is a reality to the evil in which we participate. It does not simply intrude upon us from outside. It is something with which we are deeply, intimately, and personally involved in our hearts and souls.
https://www.gotquestions.org/born-sinners.html