What is the root problem of every person, according to Paul?
According to Paul, the root problem is not what a person does but who they are: sons of Adam. Every person is born into Adam's fallen condition, with a sin-bent personality, and cannot fix it by self-effort. Only God can do what is needed.
Les teaches that the Holy Spirit convicts men by the Law of their need because they cannot do it on their own. Then the Apostle Paul lays it out plainly in Romans and Ephesians: the root problem is not primarily our actions but our identity. We are sons of Adam. Every baby born into the world is in the same place Adam was after he fell. The child may come in a sweet, innocent little body with five senses, but lying with them is a sin-bent personality. That personality can try to clean itself up, but until God does what only God can do, it is all for nothing.