Believers in Christ have been made “free from sin” by grace (Rom. 6:14,18) in the sense that they need not, indeed, should not, yield to sin when temptation arises (Rom. 6:12,13). Believers have also been made “free from the law of sin and death” (Rom. 8:2) for Christ, in grace, bore the death penalty for them.
But no believer is free from what Paul calls “the law of sin which is in my members” (Rom. 7:23), that is, the old Adamic nature, with its inherent tendency to do wrong. Nor is he free from the conflict with the new nature which this involves. If the Christian would be truly spiritual and deal in a scriptural way with the sin that indwells him, he must clearly recognize its presence; he must face the fact that while, thank God, he is no longer “in sin”, sin is still in him.
But this conflict should not discourage us, for it is one of the true signs of salvation. It is unknown to the unbeliever, for only the additional presence of the new nature, along with the old, causes this conflict, for the Bible says about these two natures: “these are contrary the one to the other” (Gal. 5:17).
But not only is this conflict within the believer a sure sign of salvation; it also creates within him a deep and necessary sense of our inward imperfection and of the infinite grace of a holy God in saving us and ministering to us daily in helping us to overcome sin. And this in turn gives us a more understanding approach as we proclaim to the lost “the gospel of the grace of God” (Acts 20:24).
Paul’s epistles show clearly that there is nothing that will so help us to overcome sin and live pleasing to God as an understanding and an appreciation of what He has done for us in Christ. As we are occupied with these “things of the Spirit” we find ourselves “walking in the Spirit”, and Galatians 5:16 says: “WALK IN THE SPIRIT, AND YE SHALL NOT FULFIL THE LUST OF THE FLESH”. How much better to have our lives transformed by occupation with Christ (II Cor. 3:18) and our position and blessings in the heavenlies with Him (Col. 3:1-3), than to assume the hopeless task of trying to improve the “old nature”; always engaged in introspection; always occupied with the flesh! source