External marks don't matter . . . what matters is faith working through love (5:6). The religious observances are not what mark us as Christ follower. We are marked by our relationship with Christ that is lived out in mission and ministry to a lost and hurting world. This life, the life marked by our relationship with Christ, is fundamentally different for the life we lived before. The previous life (Paul calls it the "life of the flesh" in 16ff) is a life that focuses on my wants, my needs, my self indulgences. It is life that is marked by being at war with all other lives for resources, prestige and status. The life of the flesh is a life that is lived outside the Kingdom of God (21).
The new life, the life that is faith working through love, is a life that bears fruit. It is significant that in this passage fruit is singular. They are not fruits of the spirit but fruit. What this tells me is that it is a package deal. Like all Greek culture lists the most important one is listed first but that listing is not hierarchical -- it is simple the first of many characteristics. The fruit of the spirit: evidence that we are living the faithful life is a life marked by Love, Joy, Peace, Patience Kindness, Generosity, Faithfulness, Gentleness, and Self Control. This fruit is not manufactured it is the result of living life in connection with Jesus. This fruit is never out of season.
How many times in recent years have we heard self proclaimed Christian speakers and politicians speak with anger, meanness and harshness (not with Love, kindness or gentleness) about their favorite issues? I am deeply concerned about our Christian witness when those calling themselves Christians show no evidence of the fruit of the spirit. We must either speak the truth in love (that is in a Christ like manner) or keep silent until we can.