For to be carnally minded is death, but to be spiritually minded is life and peace. Romans 8.6
The Lord Jesus said those who are born of the flesh are flesh and those who are born of the Spirit are spirit (John 3.6).
Those who are still flesh are carnally minded; this is, they will not listen to the direction of the Holy Spirit. And those who are spirit (born of God) will not listen to the desires of the flesh.
For this reason, in the spiritual world, there is no uncertainty: either a person is Light or darkness; either he is of God or of the devil.
To live in the flesh is to listen to the voice of the heart, which is desperately wicked and deceitful (Jeremiah 17.9).
The heart has been the cause of suffering and ruin of many people. However, when a person submits to the voice of the Holy Spirit (obeys the Word of God), he becomes strong enough to resist the desires of the flesh and remain saved in the presence of God.