Moses is talking to the adults who saw (when they were children) God save them from Egypt, who saw with their own eyes what happened to Dathan and Abiram. The land you are entereing is very fertile - more than Egypt was - so be careful not to forsake God. If you are faithful, the land will stay fertile, and you will drive out the Canaanites. If not, you will be cursed.
Don't sacrifice to God anywhere you want, in Canaan, but only the one place God appoints. You can eat meat anywhere (not the blood). Do not copy the nations in how they worship their gods.
Don't tolerate false prophets who lead you away from God. Even if your closest friend or wife suggests worshiping other gods, put them to death. If you hear of a nearby city in Israel that has gone after other gods, go investigate. If it's true, kill everyone and burn it to the ground.
How this is about Jesus
He was tempted to idolatry by Satan, and quoted Deut. 6, to worship God alone.
He is the true prophet who leads us TO God, not away from Him.
We have not seen the Exodus or crucifixion with our own eyes. We are the children of those who did, and have their writings in the Bible. Like this text, those writings are not just Moses' or the apostles' words, but God's very words (see Deuteronomy 31:9-13).