“So get rid of all evil and all deceit and hypocrisy and envy and all slander. And yearn like newborn infants for pure, spiritual milk, so that by it you may grow up to salvation, if you have experienced the Lord’s kindness.”
1 Peter 2.1-3
Growth is in the direction of salvation. Without growth, no one can be saved. There are no spiritual infants in heaven. The way to growth is through the word of God.
If you are not growing spiritually, only one solution is possible: repentance. How to yearn for God’s word? Start reading it!