Being obedient does not constitute salvation by works. You are already saved. The reason God wants us to not sin is because He knows it is not good for us, and will eventually end up killing us in one way or another. So His directive is given to us out of a heart of love, just as was the giving of His Son. There is a practical harmony or synergism between vertical faith in God and horizontal works to a needy world.
Faith is both spiritual and practical.
In view of the obedience of Christ and His lordship, the Philippians should show a like obedience. Paul does not teach that salvation is dependent on one's continued works, but that salvation must express itself in progressive Christian living and upright character, not only individually, but through obedient participation in God's corporate call to a local church.upright character, not only individually, but through obedient participation in God's corporate call to a local church. Without denying man's freedom, Paul stresses God's part in man's salvation, both in its initial resolution and in its subsequent progress.