Hebrews 5:13-14

13 for everyone who lives on milk, being still an infant, is unskilled in the word of righteousness.
14 But solid food is for the mature, for those whose faculties have been trained by practice to distinguish good from evil.
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.