“Train up a child in the way he should go: and when he is old, he will not depart from it.”
Start a child on the way he should go; even when old, he will not depart from it—an affirmation of the formative power of childhood discipline and direction, establishing that early training has lifelong consequence. The phrase 'train up' (chinokh) describes the intensive formation of youth; it involves discipline and instruction. The promise 'will not depart' suggests permanence; early formation creates grooves in the person that persist. The theological significance involves the principle that childhood is the critical window for moral formation, and that parental responsibility is sacred.