Psalms 78:37

For their heart was not right with him, neither were they stedfast in his covenant.

The heart not being right means inner loyalty was false toward God, with no lasting steadfastness in His covenant. In the wilderness this showed in failure to trust Him to give the food best fitted to preserve health, in despising the angels' food He gave as a blessing, and in lusting for flesh until He gave their desire and His wrath slew the fattest of them and smote down the chosen men while the meat was yet in their mouths. Through disobedience to His directions they mingled with the heathen, learned their works, and served their idols, and that mingling and idolatry was the outward reflection of this inward and covenantal unfaithfulness.

When trial came the same failure appeared in turning to complaint and forgetting God as the source of strength. Their seeking of Him when afflicted and slain, and their remembering Him as Rock and Redeemer, was no sincere turning, but flattery with the mouth and lying with the tongue, so that repeated return after punishment did not mean hearts made right or covenant faithfulness restored. They repented only under rebuke and chastisement and then fell again under temptation through self-indulgence and self-gratification, constantly working against a good God, and by disobedience brought upon themselves the condition that was the sure result of their own course.

Even so, in full compassion He forgave iniquity, spared them from destruction, and many times restrained and turned away anger, remembering that they were mortal flesh and frail. The psalm as a whole recounts the rich blessings God bestowed upon Israel and their poor response and poor returns for those benefits despite them, and it is given as an instructive lesson to be studied. Neglect of His instruction, including in the home, can leave children unguarded and vulnerable to influences that turn them away from faithfulness. In contrast, those who have Bible religion, with Christ abiding in them and they in Him, connected with the source of all wisdom and power and fully receiving truth of heavenly origin and sanctified through it, continually advance in the divine life and do not complain and forget in trial.