This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. But if ye be led of the Spirit, ye are not under the law. Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God. But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, Meekness, temperance: against such there is no law. And they that are Christ's have crucified the flesh with the affections and lusts. If we live in the Spirit, let us also walk in the Spirit. Let us not be desirous of vain glory, provoking one another, envying one another. - Galatians 5:16-26
As easy as it is to focus on the various lists provided in Scripture, the baseline of what Paul lays out in this passage is a process. Those that are Christ's have crucified fleshly affection and lust when they united with Him in his death...the power of sin is broken. They have new life when they are united with Him in his resurrection...the Holy Spirit lives within them and the battle begins. If there is struggle with and progress against sin then the Holy Spirit is present.
We also have a responsibility to "walk out what has been worked in":
According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue:
Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust. And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge; And to knowledge temperance; and to temperance patience; and to patience godliness; And to godliness brotherly kindness; and to brotherly kindness charity. For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ. But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins. - 2 Peter 1:3-9
Paul also says that the paradigm through which we judge ourselves and others has shifted. Even though we once judged Christ, ourselves, and others according to the flesh, according to worldly wisdom, we should no longer judge in this fashion:
For the love of Christ constraineth us; because we thus judge, that if one died for all, then were all dead: And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again. Wherefore henceforth know we no man after the flesh: yea, though we have known Christ after the flesh, yet now henceforth know we him no more. Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. - 2 Corinthians 5:14-17
Do you know someone who confesses that Jesus Christ is the Son of the living God and who, regardless of how difficult or fruitless their struggle with sin appears to be, continuously clings to the crucified and risen Lord as the only hope? Encourage such a one, judging that, according to the promises of God and not according to the flesh, this is a new creation. Flesh will fail but the promises of God are sure.