Yes, there is a battle going on with the Christian. However, when we are walking in the Spirit and being led by the Spirit, we are not fulfilling the lust of the flesh, and we are not under the law. As we return to the Cross, we look up and see that our old man has been crucified with Christ, and by the power of the Gospel, we live from faith to faith.
"Now the works of the flesh are evident, which are: adultery, fornication, uncleanness, lewdness, (20) idolatry, sorcery, hatred, contentions, jealousies, outbursts of wrath, selfish ambitions, dissensions, heresies, (21) envy, murders, drunkenness, revelries, and the like; of which I tell you beforehand, just as I also told you in time past, that those who practice such things will not inherit the kingdom of God." (Galatians 5:19-21 NKJV)
"Now the practices of the sinful nature are clearly evident: they are sexual immorality, impurity, sensuality (total irresponsibility, lack of self-control), idolatry, sorcery, hostility, strife, jealousy, fits of anger, disputes, dissensions, factions [that promote heresies], envy, drunkenness, riotous behavior, and other things like these. I warn you beforehand, just as I did previously, that those who practice such things will not inherit the kingdom of God." Galatians 5:19-21 (AMP)
Adultery – unfaithful to the marriage vows
Fornication – any sexual sins (pornography, self-gratification, homosexuality, any sexual intercourse – physical or mental)
Uncleanness – impurity of lustful, luxurious living, defiled by worldly thinking
Lewdness – unbridled lust, filthy language, disgraceful, uncontrolled tongue
Idolatry – worship false gods, the sin of the mind (putting X over God – X: job, family, recreation, sports, TV, games, eating, etc.)
Sorcery – pharmakeía – use of drugs, witchcraft, occult, use the devil for gain
Hatred – enmity, hostility, Opposite of agapé love
Contentions – strife, quarreling, debating,
Jealousies – zeal, defending anything of self, rivalry with others,
Outbursts of Wrath – passion, anger, inflamed indignation,
Selfish Ambitions – the self-seeking pursuit of politics, "party spirit," I'm the best.
Dissensions – causing divisions, standing apart,
Heresies – self-willed opinion over truth
Envy – spiteful jealousy, the displeasure of others' prosperity, want to deprive others of what they have.
Murders – slaughter or killing a human person
Drunkenness – méthē: intoxication, in bondage to alcohol,
Revelries - carousal (letting loose), partying (food and drink) all night, rioting, riotous living
And the Like – if Paul missed anything: resembling anything from the above list.
Those who habitually practice these things will not inherit the kingdom of God. It is not saying that a Christian who struggles is disqualified for heaven, but the one who has no regard for God and would rather stay in their sin – is not a Christian.