Can a good background and religious training keep an unsaved person from being overcome by the old Adamic nature?
No. A good background and religious training may inhibit or restrain an unsaved person to a certain degree, but it cannot make them victorious over the old Adamic nature. Getting victory over old Adam requires the power of God, which religious training alone cannot supply.
Les explains that the world is saturated with immorality and wickedness because unbelievers have only the old Adamic nature. He acknowledges that some are inhibited to a certain degree by their background and training, but they still cannot get victorious over that old Adam, because that takes the power of God. Whether in a believer’s moment of weakness or in the unbeliever’s lifestyle, the works of old Adam are manifest and obvious. Les points to Esau, a fornicator destitute of faith, and Ishmael, who married an Egyptian contrary to what God wanted for Abraham’s offspring. Esau also married Canaanite women already steeped in immorality and wickedness. Paul mentions sexual immorality first in his classifications of human sins.