How Do I know if I am Growing into Maturity?

I have seen various scenarios that say how we ought to grow and signs that we are mature. I must say that I have not found any that really seem to click with me.

I have tried myself to devise a system or way to see if folks are getting more mature but they all seemed to break down under close scrutiny. Then this morning I had an insight. During worship at church it suddenly struck me that scripture tells us how to judge spiritual growth. The place to look is Galatians 5 where Paul contrasts the Fruit of the Flesh with the Fruit of the Spirit.

19 The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; 20 idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions 21 and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.

It also struck me that the fruit of the flesh are all indications of a lack of peace or what we call "Emotional Reactivity" to situations and people that are greater than what is prudent. For example, a waiter spills a glass of water and some of it falls on me. What do I do as a result? An immature person will be Reactive and yell, curse, attack the waiter or threaten to sue the restaurant. A mature person will be Peaceful and reason with patience, long suffering and kindness.

22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness and self-control. Against such things there is no law. 24 Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires. 25 Since we live by the Spirit, let us keep in step with the Spirit. 26 Let us not become conceited, provoking and envying each other.

By their fruits you shall know them. Jesus