'And they that are Christ's have crucified the flesh with the affections and lusts.' Galatians 5:2
The natural life is not sinful; we must be apostatized from sin, have nothing to do with sin in any shape or form. Sin belongs to hell and the devil; I, as a child of God, belong to heaven and God. It is not a question of giving up sin, but of giving up my right to myself, my natural independence and self-assertiveness, and this is where the battle has to be fought. It is the things that are right and noble and good from the natural stand point that keep us back from God's best. To discern that natural virtues antagonize surrender to God, is to bring our soul into the centre of its greatest battle. Very few of us debate with the sordid and evil and wrong, but we do debate with the good. It is the good that hates the best, and the higher up you get in the scale of the natural virtues, the more intense is the opposition to Jesus Christ. "They that are Christ's have crucified the flesh" - it is going to cost the natural in you everything, not something. Jesus said - "If any man will be My disciple, let him deny himself," i.e., his right to himself, and a man has to realize Who Jesus Christ is before he will do it. Beware of refusing to go to the funeral of your own independence.
The natural life is not spiritual, and it can only be made spiritual by sacrifice. If we do not resolutely sacrifice the natural, the supernatural can never become natural in us. There is no royal road there; each of us has it entirely in his own bands. It is not a question of praying, but of performing.