How long does the battle between the old and new nature last?
The conflict begins at salvation and continues until the believer leaves this life, whether by death or by the Rapture. Until one of those events occurs, the old nature and new nature remain at total odds, waging a constant, unending warfare within every believer.
Les teaches that the battle lines are defined from the very moment a person is saved and continue until they leave this life—either by death or by the Rapture. Until then, the believer is in a constant warfare. The old nature declares war on the new nature, and the new nature must declare war on the old nature. The old Adam, or the flesh, lusts or wars against the Spirit, while the Holy Spirit wars against the flesh, or old Adam. These two forces within every believer are contrary; they are at total odds and cannot agree on anything. The new nature has a whole new set of values that comply with the righteousness, holiness, and laws of God. The old nature, whose god is Satan and the god of this world, is bent in rebellion and unbelief. Therefore, they are total opposites and war constantly, so you cannot do the things that you would.