14 “It is not with you alone that I am making this sworn covenant, but with whoever is standing here with us today before the Lord our God, 15 and with whoever is not here with us today.” 16-17 “You know how we lived in the land of Egypt, and how we came through the midst of the nations through which you passed. And you have seen their detestable things, their idols of wood and stone, of silver and gold, which were among them. 18-19 Beware lest there be among you a man or woman or clan or tribe whose heart is turning away today from the Lord  our God to go and serve the gods of those nations. Beware lest there be among you a root bearing poisonous and bitter fruit, one who, when he hears the words of this sworn covenant, blesses himself in his heart, saying, ‘I shall be safe, though I walk in the stubbornness of my heart.’ This will lead to the sweeping away of moist and dry alike.” 

20-21 “The Lord will not be willing to forgive him, but rather the anger of the Lord and  his jealousy will smoke against that man, and the curses written in this book will settle upon him, and the Lord will blot out his name from under heaven.  And the Lord will single him out from all the tribes of Israel for calamity, in accordance with all the curses of the covenant written in this Book of the Law.  22-24 And the next generation, your children who rise up after you, and the foreigner who comes from a far land, will say, when they see the afflictions of that land and the sicknesses with which the Lord has made it sick - the whole land burned out with brimstone and salt, nothing sown and nothing growing, where no plant can sprout, an overthrow like that of Sodom and Gomorrah,  Admah, and Zeboiim, which the Lord overthrew in his anger and wrath - all the nations  will say, ‘Why has the Lord done thus to this land? What caused the heat of this great anger?’” 

25-28 “Then people will say, ‘It is because they abandoned the covenant of the Lord, the God of their fathers, which he made with them when he brought them out of the land of Egypt, and went and served other gods and worshipped them, gods whom they had not known and whom he had not allotted to them. Therefore the anger of the Lord was kindled against this land,  bringing upon it all the curses written in this book, and the  Lord uprooted them from their land in anger and fury and great wrath, and cast them into another land, as they are this day.’ 29 The secret things belong to the Lord our God, but the things that are revealed belong to us and to our children for ever, that we may do all the words of this law.” Deuteronomy 29:14-29 (English Standard Version)

In the 1600's John Selden, an English Jurist and scholar of England's ancient laws and constitution, made a statement that is still used today. He said: “Ignorance of the law excuses no man; not that all men know the law, but because 'tis an excuse every man will plead, and no man can tell how to confute him.” Can you see how that ties in with what we read in vs 15?

When the covenant God made with Israel was renewed and written down, it took away any excuse for people who’d come in future generations to say they ‘didn’t know’ they were doing wrong. The sort of person spoken of in vs 18-19. People living generations later wouldn't have seen God's power in action as those of Moses' generation had seen, nor known the ugly practices of the Egyptians and the nations of Canaan. (vs 16-17) So they might assume that sinning against God is no big deal. Sadly, if they introduced wicked ways into Israel they would poison the nation, and would have no excuse for God to not pour out the judgements described in vs 22-24 which He had warned them about. Then, when people asked WHY such devastation had come upon Israel, the answer would be given in the words of vs 25-28.

So what is the big lesson we should take to heart from vs 29?

I suggest that even when it was explained to people why such devastation had come, there’d still be those who say, “Yes, but why has God done it this way?” Men and women often question God's ways. Moses says that it’s not for us to demand to know things that God has kept to Himself, or use that as an excuse for not doing what is right. What He has revealed through Moses and the prophets, and Jesus Christ and His apostles, is all we need to know to serve Him in the world. We can't say we didn't know His will.