Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. Because the carnal mind is enmity against God - Because it is a carnal mind, and relishes earthly and sinful things, and lives in opposition to the pure and holy law of God: therefore, it is enmity against God; it is irreconcilable and implacable hatred.
It is not subject to the law of God - It will come under no obedience; for it is sin, and the very principle of rebellion; and therefore it cannot be subject, nor subjected; for it is essential to sin to show itself in rebellion; and when it ceases to rebel, it ceases to be sin.
From this we learn that the design of God in the economy of the Gospel, is not to weaken, curtail, or lay the carnal principle in bonds, but to destroy it. As it is not subject, and cannot be subject, to the law of God, it must be destroyed, else it will continue to rebel against God. It cannot be mended, or rendered less offensive in its nature, even by the operations of God; it is ever sin, and sin is ever enmity; and enmity, wherever it has power, will invariably show itself in acts of hostility and rebellion.