Deuteronomy 32:20 - Joseph Benson’s Commentary on the Old and New Testaments

I will see what their end will be I will make them and others see what the fruit of such actions shall be. No faith No fidelity. They were notoriously perfidious, and had so often broke their covenant with God, that they were not to be trusted when they made profession of repentance. To the truth of this their whole history bears witness. But besides this, in another sense they were destitute of faith. They did not truly believe the words God had spoken to them; they had not faith either in his promises or threatenings. And they put no trust or confidence in his glorious perfections, in his power, love, or faithfulness. Alas! how justly may God make the same complaint concerning many professors of Christianity! They are children in whom is no faith. They have not a firm reliance on the truth and importance of what God has spoken, and on the divine attributes engaged to make it good. Whatever is not the object of their senses, they either believe but faintly, or not at all. Here is the great failing of most professors of the true religion, the grand source of their sins and miseries. For it is faith only that can unite man to God, and produce love and obedience: it is this only that can raise him from earth to heaven! Reader, hast thou faith? Remember, without faith it is impossible to please God. From this verse to the 29th, Moses personates God speaking.