Because the Corinthian Christians were not spiritually mature, Paul could not discuss the deeper truths of life in Christ, which are like solid food (see 1 Corinthians 2:6–7) meant for mature Christians. Instead, he had to focus on milk, the basic teachings of the good news about Jesus (compare Hebrews 5:12–14; 6:1–3; 1 Peter 2:2).