When someone trusts in Jesus Christ for salvation, it marks the beginning of a journey that will continue the rest of their life. They do not stay the same. They transform and grow to be more like Jesus. This process is called "sanctification." Like newborn babies need milk to grow before they can eat solid food, new Christians need "pure spiritual milk" to fully experience salvation (1 Peter 2:2–3). Eventually, they will be ready for the "solid food" of deeper teachings (Hebrews 5:11–14).
Spiritual maturity involves the ability to understand spiritual wisdom (1 Corinthians 2:6). The apostle Paul commands Christians to think maturely (1 Corinthians 14:20). The body of Christ matures as Christians become spiritually equipped and learn about the Son of God (Ephesians 4:11–16). This leads to a united faith community where love and truth strengthen the body of Christ.
The audience of Hebrews was spiritually immature. The author wanted to provide them with substantial spiritual teachings. But they behaved like spiritual infants who needed basic nourishment instead of deeper lessons (Hebrews 5:12). They had not been attentive to God's teachings. They had been Christians long enough to teach others, but their growing insensitivity made them spiritually dull (5:11–12; compare 1 Corinthians 3:1–3).
They lacked the maturity to understand the basic difference between right and wrong (Hebrews 5:14). Therefore, the author challenged them to grow into maturity. This was so he could share deeper truths of the faith, instead of repeatedly covering the basics (6:1–3).
Spiritual maturity does not happen automatically over time. It comes from actively listening to the word of God and living it out with a community of Christians.
Passages for Further Study
1 Corinthians 2:6; 3:1–3; 14:20; 2 Corinthians 13:9–11; Ephesians 4:11–16; Colossians 4:12; Hebrews 5:11–14; 6:1–3; 10:14; 12:1–2; 1 Peter 2:1–3