What is the relationship between the two natures inside every believer?
The old nature and new nature are contrary, at total odds, and wage constant war against each other from salvation until death or Rapture; they cannot agree because the new nature follows God's righteousness and holiness while the old nature is rebellious and unbelieving.
Les teaches that the old nature and the new nature are set against one another from the moment of salvation until the believer leaves this life by death or the Rapture. The old nature declares war on the new, and the new nature must declare war on the old, producing a constant battle. The old Adam or flesh wars against the Spirit, and the Holy Spirit wars against the flesh or old Adam. These two forces within every believer are contrary and at total odds; they cannot agree on anything. The new nature has a whole new set of values in compliance with God's righteousness, holiness, and laws, while the old nature, whose God is Satan, is bent in rebellion and unbelief. Thus they war constantly, so you cannot do the things you would.