Faithful obedience to GOD's instructions was key to Israel maintaining possession of the land.
Israel was encamped across the border from Canaan. Moses was soon to die. In his final days, Moses reminded Israel to keep GOD's ordinances, warning them of the severe consequences of disobedience. Numerous important truths are found in Moses' words.
One such truth was that obedience to GOD was essential for Israel to keep the land they were about to take control of:
1 “Now, O Israel, listen to the ordinances and judgments I teach you today to observe, that you may live and become numerous and inherit the land the Lord God of your fathers is giving you. 2 You shall not add to the word I command you, nor take from it, that you may keep the commandments of the Lord your God, all that I command you today. 3 Your eyes saw all the things the Lord our God did at Baal Peor; for the Lord your God destroyed from among you all the men who followed Baal of Peor. 4 But you who held fast to the Lord your God are alive today, every one of you.
5 “Surely I taught you ordinances and judgments, as the Lord commanded me, that you should act according to them in the land you go to inherit. 6 Therefore be careful to observe them; for this is your wisdom and your understanding in the sight of the Gentiles, who will hear all these ordinances and say, ‘Surely this great nation is a wise and understanding people.’ 7 For what great nation is there that has God so near to it, as the Lord our God is to us, for whatever reason we may call upon Him?
8 “Also, what great nation is there that has such ordinances and righteous judgments as are in all this law I set before you today? 9 Only take heed to yourself and diligently guard your soul, lest you forget all the things your eyes saw, and lest they depart from your heart all the days of your life; and you shall teach them to your sons and the sons of your sons, 10 especially concerning the day you stood before the Lord your God in Horeb on the day of assembly, when the Lord said to me, ‘Gather the people to Me and let them hear My words, so they may learn to fear Me all the days they live on the earth, and may teach their sons.’ 11 Then you came near and stood at the foot of the mountain, and the mountain burned with fire to the midst of heaven, with darkness, gloom, storm, and a great voice. 12 The Lord spoke to you from the midst of the fire. You heard the sound of the words, but saw no form; you only heard a voice. 13 So He declared to you His covenant, the Ten Commandments, which He commanded you to perform; and He wrote them on two tablets of stone.
14 “Then the Lord commanded me at that time to teach you ordinances and judgments, so you might observe them in the land you are crossing over to inherit. 15 So be careful to guard your souls, for you saw no form when the Lord spoke to you at Horeb on the mountain from the midst of the fire. 16 Do not act lawlessly and make for yourselves a carved form of any image: the likeness of male or female, 17 the likeness of any cattle on the earth, or the likeness of any winged bird that flies under heaven, 18 the likeness of anything that creeps on the ground, or the likeness of any fish in the waters beneath the earth.
19 “Also do not act lawlessly when you lift your eyes to heaven and see the sun, the moon, and the stars, all the adornment of heaven, and you thus go astray and worship and serve them, which the Lord your God assigned to all the nations under heaven. 20 But the Lord took you and brought you out of the iron furnace, from Egypt, to be His people, an inheritance, as you are this day. 21 Furthermore, the Lord was angry with me about what you said, and swore I would not cross over the Jordan and enter the land the Lord your God is giving you as an inheritance. 22 But I am going to die in this land, thus I am not going to cross over this Jordan; but you will cross over and inherit this good land. 23 Take heed to yourselves, lest you forget the covenant the Lord your God made with you and make for yourselves a carved form of anything, concerning which the Lord your God forbade you. 24 For the Lord your God is a consuming fire, a jealous God.
25 “If you beget sons and the sons of sons and dwell a long time in the land, and act lawlessly and make a carved form of anything, and do evil in the sight of the Lord your God to provoke Him to anger, 26 I call heaven and earth to witness to you today that you will be utterly destroyed from the land you are crossing over the Jordan to inherit. You will not live long on it, but will be utterly annihilated. 27 Then the Lord will scatter you among all the nations, and you will be left few in number among the nations where the Lord will bring you. 28 There you will serve different gods, the works of men’s hands, wood and stone, which neither see, hear, eat, nor smell. 29 But from there you will seek the Lord your God, and you will find Him when you seek Him with all your heart and with all your soul in your tribulation; 30 and all these words will find you at the end of days, when you turn to the Lord your God and obey His voice; 31 for the Lord your God is a merciful God. He will not forsake you nor annihilate you, nor forget the covenant of your fathers, which He swore to them.
32 “For ask now concerning former days, before your day, in which God created man on the earth, and ask from one end of heaven to the other whether any great thing like this has happened, or anything like it has been heard. 33 Did any people ever hear the voice of the living God speaking from the midst of the fire, in the manner you heard, and live? 34 Or did God ever try to go and take for Himself a nation from the midst of another nation, in testing, signs, wonders, and war, and by a mighty hand and outstretched arm, and by great visions, according to all the Lord your God did for you in Egypt before your eyes? 35 To you it was shown that you might know the Lord your God is God; there is none other besides Him. 36 Out of heaven He let you hear His voice, that He might instruct you; and on earth He showed you His great fire, and you heard His words from the midst of the fire. 37 Because He loved your fathers, therefore, He chose you their seed after them; and He brought you out of Egypt with His great strength, 38 destroying from before your face nations greater and mightier than you, to bring you in, to give you their land as an inheritance, as you have it today. 39 Therefore know today and bear in mind, the Lord your God, this God, is in heaven above and on the earth beneath; there is no other besides Him. 40 You shall therefore guard His ordinances and His commandments I command you today that it may be well with you and with your sons after you, and may prolong your days in the land the Lord your God is giving you to guard all the time.”
(Deuteronomy 4:1-40 OSB)
For Israel, it was straightforward and binary: Live faithfully to GOD and be blessed; turn to other gods and do evil and suffer, including the loss of your land.