For all who are led by the Spirit of God are [children] of God.--Romans 8:14In Romans 8, Paul contrasts a life lived under the dictates of the flesh with a life lived under the influence and control of the Holy Spirit. He argued that, “we[children of God] are debtors, not to the flesh, to live according to the flesh.”(Rom 8:12). To be a debtor to the flesh, is to be under bondage to sin and controlled by the desires of the flesh.
Living under bondage of the flesh, Paul says leads to death; “For if you live according to the flesh you will die”(vs 13).
In life we are all driven by a specific desire: success, fame, money, power, influence, pleasure etc. But as believers, we should be driven by the glory of God. The chief end of man is to glorify God and enjoy Him forever (WSC).
Where is your desire? (Ps 42: 1-2, Matt 6:33, Phil 3:10, Col 3:1). The difference between those driven by the desires of their flesh and those submitted to the Spirit is simply that, the latter are regenerated, born again and indwelt by the Spirit of God. They are sons–children–of God.
If the Spirit of God lives in you and you are truly converted, there must be a growing evidence of victory over the desires of your flesh. If there is no evidence of change and transformation in the dispositions of your heart which of course shows in your way of life, then there is a legitimate reason for your conversion to be questioned. You must be yearning and desiring to please God in all you do.
For to set the mind on the flesh is death, but to set the mind on the Spirit is life and peace. For the mind that is set on the flesh is hostile to God, for it does not submit to God’s law; indeed, it cannot. Those who are in the flesh cannot please God. You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him" (Rom 8:7-9).
There is a Litmus test for who is a child of God! Is yours a mind set on the flesh or a mind set on the Spirit? The best judge is you if indeed you belong to Christ: “Examine yourselves, to see whether you are in the faith. Test yourselves. Or do you not realize this about yourselves, that Jesus Christ is in you?—unless indeed you fail to meet the test!(2 Cor 13:5).