Growing Up

As parents, we desire that our children grow up to be sensible, mature adults with good character. Everybody grows up physically, but not everyone grows up mentally and emotionally—and spiritual maturity is another matter entirely.

One can find numerous articles and scientific studies about human growth and development in areas of human maturity, including physical, mental, and emotional maturity, which are all debated in different branches of science. Most would agree that growing to maturity is a process that takes time, and that reaching maturity takes longer for some than for others.

There are some average age ranges at which maturity in various areas is reached. For example, an article titled “The five ages of the brain: Adulthood” in New Scientist magazine states that the human brain’s powers reach peak at about 22 years of age and last about five years. Various abilities arrive and then decline at different rates. After that, the brain’s processing speed slows down and working memory stores less information. (No wonder I get as frustrated with my memory as I do with my computer!)

A similar conclusion is shared in a Psychology Today article titled “What It Really Means to Be Mature,” which says, “Medical science has shown that adolescence continues into one’s 20s when the frontal lobe fully comes on board by age 26.” That seems familiar to my own experience and the observations of many others who are now past those developmental years.

When it comes to spiritual maturity, the Bible does talk about the need for Christians to “grow up” into mature followers of Christ. Samuel is an example of a child growing up into a spiritually mature man. As a child, he was dedicated to tabernacle service: “And the child Samuel grew in stature, and in favor both with the Lord and men” (1 Samuel 2:26).

Jesus went through stages of human growth that we also experience—but He was without sin. Isaiah prophesied of Jesus, “He shall grow up before Him as a tender plant” (Isaiah 53:2), and Jeremiah prophesied, “I will cause to grow up to David a Branch of righteousness” (Jeremiah 33:15). Luke says that “Jesus increased in wisdom and stature, and in favor with God and men” (Luke 2:52).

Christ gave His true ministers for “the equipping of the saints… till we all come in the unity of the faith and of the knowledge of the Son of God… to the measure of the stature of the fullness of Christ; that we should no longer be children… but, speaking the truth in love, may grow up in all things into Him who is the head—Christ” (Ephesians 4:11–15). That is what spiritual maturity is—to be like Jesus Christ.

That maturity can be defined as having many attributes, such as those listed in the rest of Ephesians 4, including not lying or stealing (vv. 25, 28) and putting away bitterness, wrath, anger, and evil speaking (v. 31). Other attributes of spiritual maturity are the fruits of the spirit as listed in Galatians 5—love, joy, peace, longsuffering, kindness, goodness, faithfulness, gentleness, and self-control (vv. 22–23).

Jesus plainly told His disciples: “Therefore you shall be perfect, just as your Father in heaven is perfect” (Matthew 5:48). The Greek word here translated “perfect” is teleios, and it refers to the state of being “complete… in various applications of labor, growth, mental and moral character” (Strong’s Exhaustive Concordance, BibleHub.com).

Of course, reaching this state is a lifelong process for all of us, and it requires that we regularly spend time taking in God’s word and applying it to our lives. “All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work” (2 Timothy 3:16–17).

For more about the necessity of spiritual growth, you can request your own free copy of What Is a True Christian?, or read it right here at TomorrowsWorld.org.