Deuteronomy 4 - 7

As the children of Israel are about to go across Jordan and possess the land promised to them, Moses tells them -

"Take heed unto yourselves, lest ye forget the covenant of the LORD your God, which he made with you..." (Old Testament Deuteronomy 4:23)

And that they will possess this land of promise as long as they keep the covenants they have made, that is -

"...When thou shalt beget children, and children's children, and ye shall have remained long in the land, and shall corrupt yourselves, and make a graven image, or the likeness of any thing, and shall do evil in the sight of the LORD thy God, to provoke him to anger:
26 I call heaven and earth to witness against you this day, that ye shall soon utterly perish from off the land whereunto ye go over Jordan to possess it; ye shall not prolong your days upon it, but shall utterly be destroyed.
27 And the LORD shall scatter you among the nations, and ye shall be left few in number among the heathen..." (Old Testament Deuteronomy 4:25 - 27)

This blessing and warning isn't much different than that to which was given to Lehi where he states -

"I, Lehi, prophesy according to the workings of the Spirit which is in me, that there shall none come into this land save they shall be brought by the hand of the Lord.
7 Wherefore, this land is consecrated unto him whom he shall bring. And if it so be that they shall serve him according to the commandments which he hath given, it shall be a land of liberty unto them; wherefore, they shall never be brought down into captivity; if so, it shall be because of iniquity; for if iniquity shall abound cursed shall be the land for their sakes, but unto the righteous it shall be blessed forever." (Book of Mormon 2 Nephi 1:6 - 7)

And if -

"...the time cometh that they shall dwindle in unbelief, after they have received so great blessings from the hand of the Lord...behold, the judgments of him that is just shall rest upon them.
11 Yea, he will bring other nations unto them, and he will give unto them power, and he will take away from them the lands of their possessions, and he will cause them to be scattered and smitten." (Book of Mormon 2 Nephi 1:10 - 11)

For as the Lord stated -

"For I am no respecter of persons..." (Doctrine and Covenants Section 1:35)

As Moses review the commandments they had received to prosper in the land, he says -

"NOW these are the commandments, the statutes, and the judgments, which the LORD your God commanded to teach you, that ye might do them in the land whither ye go to possess it..." (Old Testament Deuteronomy 6:1)

And with the commandments and statutes, Moses gives the first and great commandment -

"...And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might." (Old Testament Deuteronomy 6:5)

With this commandment -

"...these words, which I command thee this day, shall be in thine heart" (Old Testament Deuteronomy 6:6)

Not just a mindful daily obedience but written in the desires of one heart. And just as modern day prophets have declared in the "The Family - A Proclamation to the World", Moses continues -

"...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." (Old Testament Deuteronomy 6:7)

Modern day instruction from the Lord's Prophets include -

"Husband and wife have a solemn responsibility to love and care for each other and for their children. “Children are an heritage of the Lord” (Psalms 127:3). Parents have a sacred duty to rear their children in love and righteousness, to provide for their physical and spiritual needs, to teach them to love and serve one another, to observe the commandments of God and to be law-abiding citizens wherever they live. Husbands and wives—mothers and fathers—will be held accountable before God for the discharge of these obligations." (The Family - A Proclamation to the World)

"...I am God...and I will show unto the world that I am the same yesterday, today, and forever..." (Book of Mormon 2 Nephi 27:23)