Deut 6:7, 20-25, 2 Tim 3:14-15, Acts 5:42

In the Old Testament, God commanded the Israelites to teach their children what God had done. (Deuteronomy 4:9-10, Deuteronomy 6:7,20-25)

Deuteronomy 4:9 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; 10 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 shall live upon the earth, and that they may teach their children.

Deuteronomy 6:7 And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up. 20 And when thy son asketh thee in time to come, saying, What mean the testimonies, and the statutes, and the judgments, which the Lord our God hath commanded you? 21 Then thou shalt say unto thy son, We were Pharaoh's bondmen in Egypt; and the Lord brought us out of Egypt with a mighty hand: 22 And the Lord shewed signs and wonders, great and sore, upon Egypt, upon Pharaoh, and upon all his household, before our eyes: 23 And he brought us out from thence, that he might bring us in, to give us the land which he sware unto our fathers. 24 And the Lord commanded us to do all these statutes, to fear the Lord our God, for our good always, that he might preserve us alive, as it is at this day. 25 And it shall be our righteousness, if we observe to do all these commandments before the Lord our God, as he hath commanded us.

We must always teach and preach that Jesus is the Christ through the Old and New Testaments. (2 Timothy 3:14-15, Acts 5:42)

2 Timothy 3:14 But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; 15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.

Acts 5:42 And daily in the temple, and in every house, they ceased not to teach and preach Jesus Christ.