Why does the Bible say Milk is one who is unskillful — Hebrews 5:13?

“For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. For every one that useth milk is unskilful in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.” Hebrews 5:12–14

The context of verse 13 (highlighted) is the reference to new believers (milk) and more experienced believers as (meat)

A newborn baby must continue to grow after birth, so must new believers continue to grow in faith, in wisdom, and in holiness to become more like Jesus (2 Peter 3:18). If a baby does not grow after it is born, something is wrong. All birth results in growth. We grow at different rates and in different ways, but growth is evidence of life.

When Jesus told Nicodemus that he “must be born again” in order to see the kingdom of God (John 3:3), He was using a metaphor. Babies don’t strain to grow every day. They grow because they are alive. When we are born of the Spirit, the Holy Spirit of God moves into our hearts and begins to change us from the inside out.

Growing as a new believer is not ultimately a matter of changing outward behaviors. It is a work of the Spirit on the inside. Upon our exercise of faith (Romans 10:9–10), He begins to transform our thoughts, our attitudes, our desires, and our perspective to be more like His. Growth is not brought about by a fleshly effort to clean up our act. It is the Holy Spirit’s work in us that causes us to want to pursue godliness. If no such desires exist, then it is likely that no new birth has occurred (James 2:17–18).

Another key to growing as a new believer is recognizing the importance of God’s Word in this new life of faith. Just as the regular intake of milk is critical for a baby’s growth and development, so God’s Word is critical for new believers.

“As newborn babes, desire the sincere milk of the word, that ye may grow thereby:” 1 Peter 2:2

There are many thought patterns to replace, attitudes to reform, and behaviors to alter as a sinner becomes a saint.

“I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.” Romans 12:1–2

Our minds are renewed as we allow God’s truth to replace the world’s lies. That continual renewal produces spiritual growth.

Another key for growing as a new believer is seeking godly fellowship. Most of the New Testament is written to churches, not individuals. The importance of Christian fellowship cannot be overstated. But fellowship involves more than simple church attendance as a spectator. Believers are the church (Ephesians 1:23; Colossians 1:18). Each member is a part of Christ’s Body on earth (Ephesians 1:22). Together we reach the lost world, minister to each other, and practice unity that prepares us for heaven. New believers must find a church that teaches God’s Word, get involved in serving, and develop healthy relationships with other believers (Proverbs 27:17).

Before we knew Jesus, we did what we wanted to do according to our lusts and passions (1 Peter 1:14). We obeyed our flesh. Learning to crucify that flesh and live according to the Spirit is a crucial part of living as a Christian (Ephesians 5:16, 25). The Bible calls this “walking by the Spirit.” Growing believers continually surrender more and more areas of their lives to Christ and let go of their right to control things.

Another important step in growing as a new believer is guarding what we allow into our minds and hearts. ”Keep thy heart with all diligence; for out of it are the issues of life.”Proverbs 4:23

The closer our walk with God, the more we will feel like “strangers and pilgrims” here on earth (1 Peter 2:11). Our appetites begin to change; we evaluate our entertainment choices, our friendships, our habits, and our thought lives, asking, In growing as a new believer, we saturate our lives with worship, praise, prayer, Scripture, godly relationships, purity, and wholesome entertainment (Philippians 4:8).

Growing as believers in Christ is a lifelong process. We never reach the place where we can say, “I have arrived. I no longer need to grow.” Even the apostle Paul did not consider himself to have “arrived” (Philippians 3:12). Growing in wisdom and maturity keeps us working in harmony with God’s plan for our lives. And we learn that the more we study, the more we learn about God, the more there is to know and this process is the transition from milk to meat.