Deuteronomy 4:9-10 Only take heed to thyself, and keep thy soul diligently, lest thou forget the things which thine eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them thy sons, and thy sons’ sons; Specially the day that thou stoodest before the Lord thy God in Horeb, when the Lord said unto me, Gather me the people together, and I will make them hear my words, that they may learn to fear me all the days that they live upon the earth, and that they may teach their children.
On the plains of Moab, Moses reminds the people to take care to keep the soul (mind, will, and emotions) so that they would not forget the Gospel of Salvation which they have seen and heard nor the Law of God given in the Covenant Commandments.
Gather the people together to hear God’s Word so that they may fear and love God all the days of their lives. So God’s people have done through the centuries in weekly synagogue worship every Sabbath and in church worship every Sunday. We respond to God’s love by assembling to hear the Word of Law and Gospel, so that we do not drift away from God, or forget what He has done, or lose fear (faith) and love of God.
And furthermore, teach Law and Gospel to your children and grandchildren, so that the Lord will remain in their lives for generations. Just as it’s possible for one person to lose faith and forget God, so it is possible for generations and people groups to lose and forget. Therefore, the Church’s response is to support and grow divine services, Sunday schools, Bible studies, and mission work.