Deuteronomy 7:12
Wherefore it shall come to pass, if ye hearken to these judgments, and keep, and do them, that the LORD thy God shall keep unto thee the covenant and the mercy which he sware unto thy fathers: Wherefore it shall come to pass, if ye hearken to these judgments, and keep, and do them, that the LORD thy God shall keep unto thee the covenant and the mercy which he sware unto thy fathers:
The Lord will keep toward His people the covenant and mercy He swore to their fathers if they hearken to His judgments and keep and do them. His faithfulness to the obedient is to love, bless and multiply them with children, crops and livestock, fruitfulness and abundance in the land and enlargement of their possessions, and to give health and protection from sickness as the Physician of soul and body. He gave the law from Sinai in awful grandeur so that by obedience they would be a holy, pure and happy people, a kingdom of priests blessed above all people and marvels of prosperity before the nations, revealing His glory and restoring His moral image in humanity. The same hearing and doing is required now, for the day of God's great final review is near, and salvation rests on keeping His covenant, since only tried commandment keepers who love God supremely will be welcomed by Christ into the golden city where there will never be another rebellion. That obedience is loyalty to God and evidence of being truly His people, requiring full surrender and continuing simplicity in keeping all His commandments according to His special directions rather than human judgment or human-made law, for His long-suffering does not mean persistent transgression will go unpunished.
Covenant Condition and Blessing
The keeping of covenant and mercy sworn to the fathers is made conditional on hearkening to the judgments and keeping and doing them, so that obedience is the stated condition for receiving covenant faithfulness. If the people listen to the judgments and obey them, the Lord keeps toward them what He swore, tying His faithfulness to that oath.
That promised mercy runs to a thousand generations, reaching to the end when all in the world who served God are translated and the dead are called forth. Then Christ comes for them, and the gates of the holy city are opened for the nations that kept the truth to enter in and see the King in His beauty.
In that setting covenant faithfulness meant love and blessing and multiplying, with increase of children, crops and livestock, fruitfulness and abundance in the land, and possession and enlargement of the land. Obedience would be met by love and blessing, including fruitful land and increase. The promises of love, blessing and increase belong to keeping the commandments and to the requirements for being a holy people.
Obedience would also be met with health and protection from sickness, including freedom from the evil diseases of Egypt, with removal of all disease and not one feeble person among the tribes. To an obedient people God would be a Physician of soul and body, preserving them from the diseases afflicting other nations and blessing them with vigor of intellect, with wisdom and skill ennobled and elevated by God as teacher. That protection from the diseases of other nations and that vigor of intellect were part of the prosperity and blessings planned for them.
The law was given from Sinai in awful grandeur and majesty so that by obedience Israel would stand in Canaan as a pure, happy and holy people. By obedience they would be marvels of prosperity before the nations, a kingdom of priests and princes furnished to become the greatest nation on earth and blessed above all people. In all that prosperity they would reveal the glory, majesty and power of God, while their worship and way of life restored His moral image in humanity. By conformity to the principles governing the hosts of heaven they would stand before all nations exemplifying true righteousness as a model of what His church should be, and through them Christ's kingdom was to extend over the earth.
Obedience Required Today
The same obedience demanded of ancient Israel is demanded now, for the day of God's great final review is near when all must stand before the Judge of all the earth, and the present is the time of investigation when every character is investigated and every case is decided for eternity. Hearing and obeying is the condition on which the keeping of covenant mercy rests, and the warning still applies now, so that on obedience depends salvation. God has respect to the obedient and lets His blessing rest upon those who keep His covenant, and that promise runs to a thousand generations reaching to the end when all who served God are translated and the dead are called forth and Christ comes for them and the gates of the holy city are opened for the nations that kept the truth to enter in and see the King in His beauty. Only tried commandment keepers who love God supremely will be welcomed by Christ into the golden city, for He will bring no father or mother or children who would not keep His commandments in this world to spoil the heavenly courts, because there has been one rebellion and there will never be another.
The verse states the conditions of all true prosperity with which all of God's institutions must comply in order to fulfill the purpose of their establishment. Obedience is the response of loyalty to God and the evidence that those who claim to be Christians are truly His people, for Christ died to bring transgressors back to keeping God's law. It requires beginning with full surrender and continuing in simplicity of obedience to all His commandments according to His special directions, neglecting none of the important things specified in His Word. It calls for diligent attention to God's voice and commands rather than human judgment or people's own ideas of what is right, and for upholding God's law rather than a human-made law, since its promises of love and blessing and increase are linked to keeping His commandments and are of great consequence.
God's long-suffering and compassion and love do not mean that persistent transgression will go unpunished, for continued rebellion and obstinacy eventually bring punishment. Disregarding the conditions and following selfish ways dishonors God and brings sickness and disease and plagues, whereas keeping His statutes and obeying His commandments brings removal of all disease. Trusting Christ as healer does not remove the need to restrict the animal appetites, because healing remains tied to obedience. With the whole of Deuteronomy 7 and Deuteronomy 1 and 8, the verse stands as the Lord's own words written for admonition for those upon whom the ends of the world are come. It is to be read as a solemn charge and lesson, to be read carefully and regarded with special interest in hearkening to these judgments and keeping and doing them, while every soul must search the Scriptures for himself and make the Word his study book and sanctify himself daily lest he be found in rebellion, so that the Lord will be glorified through His obedient people. Parents are to read the fifth and sixth and seventh chapters of Deuteronomy to correct sinful neglect of training their children from very infancy to form characters that will meet God's approval, with God's words in the heart and taught diligently to children when sitting in the house and walking by the way and lying down and rising up.