Certain people are mature at 10 years old, others at 12 years old, others at 25 years old, others not until 50 or 60 years old. Some people never grow up into maturity.
The road to maturity involves learning to shuck the quest for instant gratification, which is wanting what you want immediately when you want it, without taking into account the future effects of the decision. Those desires for instant gratification is calling lacking in maturity.
I said in My Instruction Book that before a man leaves on a journey that the man must wisely take into account his plans and the effects of the plans on his journey. That comes from maturity of the will or the decision making ability of the person.
To be weak willed is to be constantly motivated by your emotions rather than your reasoning and strong will.
Emotional immaturity is the common denominator behind all sins, trespasses and transgressions of the flesh. It results from making quick, unreasonable responses to life's adventures, not discerning that they are from the devil who uses your emotions to influence your decisions rather than you using your reasoning power to make your decisions. Emotional responses will curse you every time.
I didn't make quick decisions when I created the earth. I never got in a hurry. You should do the same thing, refuse to make quick decisions which are instigated by emotions influenced by evil spirits who want to trap you into wrong decisions.
Learning to listen to and heed the inner voice of wise reason is what leads a person to be mature and productive. Mature people are not influenced by nonproductive friends, rebellious acquaintances or entertainment heroes. Mature people are influenced by that still, small voice of reason, which is My voice, the wise voice of reason which leads you into productive activities.
Let your motto be to Stop immediately, Look at the situation with reasoning abilities, then Listen to My voice inside of you which will influence your decision making in the right direction, the direction of prosperity of body, soul and spirit.
Psalm 1; Proverbs 3:13-22; Proverbs 10:14; Proverbs 10:23; Proverbs 11:12; Proverbs 12:8; Proverbs 13:20; Proverbs 15:21-24; Proverbs 17:28; Proverbs 29:8.