For every one that useth milk is unskilful in the word of righteousness: for he is a babe. —Hebrews 5:13, KJV
Solid food is nourishment by which the capacity of the soul is enlarged. Sooner or later, a newborn baby must go from milk to something solid; if that does not happen, there will be a deformed child. It is the same with the analogy here.
What do I mean when I say solid food is nourishment by which the capacity of the soul is enlarged? The soul's enlargement will mean simple trust in God, unfeigned love for one another, and the ability to understand what God is pleased to reveal. Now by simple trust in God, I would remind you of 1 John 4:16: "We know and rely on the love God has for us." That verse has gripped me for years. But it involves simple trust, simply taking seriously that God really does love us. When one really believes it, it changes everything. The ability to digest solid food is the enlargement of the soul, where you become able, simply in a childlike way, to trust in God. Jesus said, "Anyone who will not receive the kingdom of God like a little child will never enter it" (Mark 10:15). Christians need to rediscover this simple trust in God, which is the soul's enlargement.
I am referring to the ability to perceive God's will. That has to do with aptitude to receive what God wants to say. It is understanding His Word, and it is knowing His direction for today. It is His Word and His will.
Understanding His Word is simply being able to read the Bible and know what it means, that God speaks to you. Maturity includes seeing His will. By this I mean that you know God so well that you know what He is thinking. It's the same with my wife: I do not have to tell her or ask her what she thinks; I already know. When you know God, you know His will.
Excerpted from Are You Stone Deaf to the Spirit or Rediscovering God? (Christian Focus Publications Ltd., 1994, 1999).