13 For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe.
There are three characteristics of those who are spiritually immature:
—they are unskilled in the Bible
—they do not apply principles of Scripture to experience
—they are spiritual infants
The “for” here gives the reason for verse 12. Anyone who lives strictly on milk has the problem of spiritual infancy.
everyone who partakes only of milk
Immature believers take only a portion of what they need to grow spiritually—still at the mother’s breast stage after many years as Christians. The Hebrew Christians were satisfied to make milk their sole diet.
is unskilled [untried]
The Greek word for “unskilled” means lacking faculty or capacity to understand. “Unskilled” also carries the idea of being inexperienced. An inexperienced person is untried in spiritual truth. The issue is not that immature believers simply lack information but that they do not know how to apply truth to their experience. Without this operating principle, they cannot mature in their faith.
in the word of [about] righteousness,
The “word of righteousness” is God’s revelation about Christ and the church. The teaching about righteousness is the teaching of the New Testament. It is the instruction that Christ is our righteousness; He achieved what we need to be righteousness before God. He presents the believer right before God.
for he is a babe.
The Greek word for “babe” means a child who has not been weaned from its mother’s breast, an infant. Here the word “babe” refers to immature Christians.
Immaturity is dangerous.
It is dangerous to remain a babe in spiritual truths. There is a culpability for one to remain at the beginning stage of spirituality. To stay in spiritual stupidity puts a person into the danger of believing false doctrine.
Adults drink milk but it is not their exclusive diet. Infants drink milk as their exclusive diet. The person who exclusively drinks spiritual milk after 10 years of being a Christian is stuck in spiritual immaturity.