New Defender's Study Bible Notes
5:12 ought. This is a strong word, meaning “have a duty.” The Jewish Christians to whom the author was writing were still involved in legalism and in speculations about the nature of Christ. They had professed faith in Christ, but were still “babes,” needing spiritual milk (I Corinthians 3:1).
5:12 oracles of God. The “oracles of God” is a striking synonym for the Scriptures. See Romans 3:2; I Peter 4:11; Acts 7:38.
5:13 useth milk. See I Peter 2:2. Babes in Christ need to feed on the milk of the Word, but they should not always remain babes.
5:14 of full age. “Of full age” is literally “of mature maturity,” essentially the same as “perfection” (Hebrews 6:1).
5:14 senses. “Senses” here means “esthetic senses” (Greek aistheterion), used only this once in the New Testament. It implies a sort of spiritual intuition, by which the sensitive Christian can more or less automatically discern whether something is right or wrong. However, this sense is developed only by attaining real maturity in the Scriptures.