“Only take care, and keep your soul diligently, lest you forget the things that your eyes have seen, and lest they depart from your heart all the days of your life. Make them known to your children and your children’s children—” (Deuteronomy 4:9, ESV)
A basic principle of the book of Deuteronomy is this: obedience to the Lord’s commands brings blessing; disobedience brings a curse. The Lord commands that we teach this truth to our children for it underlies all of life, even today, although the understanding of what blessing and destruction may differ. In the case of Israel, blessing meant prosperity and descendants; the curse meant slavery, exile, and the loss of land. For Christians blessing means joy, peace, freedom from the fear of death, and the assurance of eternal life, while the curse means discipline, judgment and punishment. Yet for Christians there is always hope in the punishment: God has not abandoned us. He will surely show mercy if we repent and seek Him with all our heart.
As for those for those who reject God, they may be blessed with prosperity in this life. But destruction for them comes in the form of unhappiness, guilt, slavery to their passions and possessions, the lack of meaning and purpose and, finally, eternity in hell if they do not repent.
Disobedience in Deuteronomy is described in terms of worshiping other gods, usually in the form of idols and statues or the forces of nature such as rain, storms, the sun, moon, stars and planets. Idolatry today comes in the form of the pursuit of materialism, money, philosophy, mysticism, sex, pleasure, food, computer games, entertainment, fame or anything else that individuals value and seek more than they value and seek for God.
The gods worldly people manufacture allow them to fulfill the desires of the flesh while reaping disease, sadness, fear and violence. But Almighty God is unique. He is one. He alone is God. He alone has acted in history, He alone has proven Himself. He alone is merciful. He alone has spoken. He alone has delivered us from sin and death through the sacrifice of Christ Jesus. Jesus fulfilled the Law of God on our behalf through His perfect obedience to the Father.