Intro.
1. Spiritual maturity is desired by all conscientious Christians - Matt. 5: 48; Phil. 3:12; Eph. 4:13; Col. 1:28.
2. "Spiritual maturity" has taken on some unscriptural definitions:
a. "Open-mindedness" (i.e., tolerance & compromise) - 1 Tim. 6:20-21.
b. Always questioning but never being definite - 2 Tim. 3:7.
c. Free-thinking (atheists / agnostics) - Rom. 1:21-22.
d. Emotionalism (regardless of revealed truth) - Jer. 10:23.
e. Bible knowledge (without obedient faith, worthless) - 2 Pet. 3:18.
3. TELEIOS - "brought to its end, finished; wanting nothing necessary to completeness; perfect; that which is perfect; consummate human integrity and virtue; of men -- full grown, adult, of full age, mature" (Online Bible, #5046).
4. The preaching of the gospel is intended to perfect us in Christ - Col. 1:28. How do we reach / secure spiritual maturity?

I. BY PUTTING AWAY CARNAL THINGS (1 Cor. 13:11).
A. Put Away Sin - 1 Cor. 3:1-3 (Col. 3:5-9).
1. Immaturity / undeveloped spirituality (3:1) will soon give way to anti-spiritual conduct (3:3). The flesh controls rather than the spirit.
a. This is the cause of contentions / strife / sin (cf. 1:11).
b. If these things exist, we are not spiritual mature!

II. BY CULTIVATING YOUR UNDERSTANDING OF TRUTH - 1 Cor. 14:20; Eph. 5:17; Jno. 8:31-32.
A. Word Of Christ Must Dwell Richly Within Us - Col. 3:16; Jas. 1:21.
1. The instrument of our obedience - Jas. 1:22-25 (3:2).
2. Able to give answer to others - 1 Pet. 3:15.
B. The Mature Use Their Understanding Wisely - Jas. 3:13-18.

III. BY STRIVING TO BE LIKE CHRIST - Eph. 4:13, 15.
A. The Maturing Christian Measures Himself By Christ.
1. By the stature of His character/conduct - 1 Jno. 2:5-6 (1 Pet. 2:21).
a. Is faith present? - Heb. 11:6
b. Is the humble mind of Christ a part of you? - Phil. 2:5
B. Christ Must Be Formed Within Us - Gal. 4.19 (2:20).

IV. BY PROGRESSING BEYOND FIRST PRINCIPLES - Heb 5:12- 6:1 (Press beyond first principles to perfection - 6:1-3).
A. In Our Understanding & Use Of Truth - 5:11, 13.
-The mature are given to comprehending & using truth.
B. In Our Willingness & Ability To Teach Truth - 5:12.
-The mature are given to teaching what they have learned.
C. In Our Ability To Discern Right & Wrong, Truth & Error - 5:14; Phil. 1:9-11 (Lk. 12:57; Jno. 7:24).
-The mature are able & willing to discern (judge, separate) sin & error from righteousness & truth!

V. BY OVERCOMING TEMPTATION - 1 Jno. 2:14 (1 Pet. 5:8-9).
A. The Word Of God Abides In The Strong - Psa. 119:11.
-This is not merely quoting scripture -- Walking in truth.
B. By Diligently Increasing In Every Fruit Of Righteousness - 2 Pet. 1:5-11. (cf. 1 Cor. 10:12-13)

Conclusion
We have a mandate to mature! (2 Pet. 3:18) How are you doing?