Are we sinners because we sin, or do we sin because we are already sinners?
We are not sinners because we sin; rather, we sin because we are sinners. The root is our birth: we are sinners because we are born of Adam. So sinful acts flow from what we already are, not the reverse. This order matters when understanding sin and God's sovereign dealings with people like Pharaoh.
Les explains that the normal person thinks, “If I wouldn't have stolen, or if I wouldn't have gotten drunk, I wouldn't have this sin problem.” But Scripture reverses that: we are not sinners because we sin; we sin because we are sinners, and we are sinners because we are born of Adam. He then illustrates with Pharaoh: when God put him on the spot, Pharaoh bristled and said he would not let the people go, hardening his own heart. Pharaoh had a choice, and of his own volition he rejected God's offer of taking Israel out of Egypt. The root condition precedes the acts.