Romans 8:7-9

the mind of the flesh [with its sinful pursuits] is actively hostile to God. It does not submit itself to God’s law, since it cannot, and those who are in the flesh [living a life that caters to sinful appetites and impulses] cannot please God. However, you are not [living] in the flesh [controlled by the sinful nature] but in the Spirit, if in fact the Spirit of God lives in you [directing and guiding you]. But if anyone does not have the Spirit of Christ, he does not belong to Him [and is not a child of God]. [Rom 8:14]