But if you are led by the Spirit, you are not subject to the law. Now the works of the flesh are obvious: fornication, impurity, licentiousness, idolatry, sorcery, enmities, strife, jealousy, anger, quarrels, dissensions, factions, envy, drunkenness, carousing, and things like these. I am warning you, as I warned you before: those who do such things will not inherit the kingdom of God.
By contrast the fruit of the Spirit is love, joy, peace, patience, kindness, generosity, faithfulness, gentleness, and self-control. There is no law against such things. And those who belong to Christ Jesus have crucified the flesh with its passions and desires. If we live by the Spirit, let us also be guided by the Spirit. Let us not become conceited, competing against one another.
(Lectionary, New Revised Standard Version)
Paul sees the flesh and the Spirit as fighting each other, within us. This would not be a fight for many people whose consciences are flexible, but for the Christian it does bring conflict. We may find no problems with rejecting some desires of the flesh like idolatry, or sorcery. While others like fornication that includes a ban on sex before marriage would not suit many in today’s world. But what about things like enmity, jealousy, anger, factions, and envy? How often do we say “I can never forgive them”? Or what about the times we have been jealous or envious of others, or we have allowed anger to screw up our mind? And as for 'factions', well this could include racist or misogynist comments or thoughts, or support of far right or far left political groups with such views.
After this, Paul goes on to list the fruits of the Spirit. We should note that these are not our fruits. They are the Spirit's fruits, those He helps us to work towards attaining. We know we are sinners but we love God, and when we try to overcome our weaknesses and resist the things of the flesh then the Spirit is there to support us. As many Christians have found, once we focus on God and resist temptation it can get easier the next time, with the Spirit's help.
The German-Dutch Canon, Thomas a Kempis (c1380-1471 CE) wrote:
Sorry folks, irresolute women are also tempted!
Lord Jesus Christ,
help us not to have a 'wavering mind'
or lose our trust in You.
May we not be like a rudderless ship
driven one way and the next.
Keep us strong in our faith,
able to fight off temptations,
and to steer an even course,
with help from the Holy Spirit.
Amen.
If you would like to know more about Thomas à Kempis, this site is quite good: