Dave Rich returns for Lesson 25 in the Christian Ethics and the Old Testament series. After establishing Scripture's authority through inspiration last session, this lesson works through the next essential questions: Is the Bible clear enough, necessary enough, and sufficient enough to serve as the foundation for Christian ethics?

Rich opens with the doctrine of the clarity of Scripture—what theologians call perspicuity—grounding it in passages from Deuteronomy, Psalms, and the New Testament epistles. The argument is straightforward: if the Word was given to ordinary Israelites, to children, to simple people across all kinds of circumstances, it is clear enough for Christians to use it for ethics. But Rich is careful to walk through honest qualifications. The unregenerate cannot fully understand Scripture. Clarity grows through study and obedience. No one comprehends all of it perfectly.

From clarity, the lesson moves to necessity. Could a believer do ethics without the Bible? Rich uses a thought experiment to show why the answer is no—conscience and general revelation together are simply not enough. The Bible is the only transcript of God's words and therefore the only source of absolute ethical norms.

The final section addresses sufficiency. Drawing on 2 Timothy 3 and Psalm 119, Rich argues that Scripture contains everything God requires us to know to live rightly—not as a ceiling on learning, but as a complete and binding standard. Nothing may bind the conscience that is not found there. Nothing is sin that Scripture does not call sin.

This lesson lays the groundwork for everything that follows in the series.