What does it say?
Psalm 78: The psalmist begins to tell of the Lord in a parable. That they should trust in God, keep his commandments (The Ten Commandments) and teach them to their children. The sons of Ephraim turned back from the enemy in fear because they forgot the works that God did when leading them out of Egypt and in the desert. Despite seeing his works, they did not trust that God would provide for them in the desert. God provided them with manna for bread and qual for meat, but they gathered these in greed and did not thank the Lord, nor believe in his wonderful works. However, when God’s anger rose and he killed some of them, they sought him, but their heart was not steadfast towards him and they did not keep his covenant. They continually rebelled against God despite all the wonderful things that he did for them and seeing with their own eyes his mighty works. God brought the children into the land that he promised the fathers and the generations that followed rebelled against the Lord, so he abandoned the dwelling place at Shiloh and the enemy struck Israel. God awoke as if he had been sleeping and drove back the enemies of Israel; however, he did not choose Ephraim as his dwelling place but chose the tribe of Judah and Mount Zion; God took David his servant out of the sheepfolds to shepherd the people.
Psalm 79: The nations were allowed to destroy Jerusalem, to defile the temple and scatter the bodies of the people, so that the beast of the earth feed on them. The psalmist prays to the Lord to come to their aide, forgive their sins and return to the neighbors sevenfold what they have done to Judah; after this, the psalmist vows that the people will give thanks to the Lord forever and tell all generations.
What does it mean?
Jesus said to the pharisee Nicodemus, “Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God.” (Jn 3:3) Unless a man is regenerated by God, he cannot believe in the Lord, nor can he observe the Lord’s commandments. Israel saw with their own eyes the mighty works of God, yet they did not believe in the Lord and did not keep his covenant. The Lord God continually came to their aide and provided for them, demonstrating his slowness to anger and his steadfast love. God will not leave the guilty unpunished; therefore, he gave them over to destruction and their scattered bodies were eaten by beasts. A man might have worldly sorrow because of what his choices have led too and he might even make vows to God if he will deliver him, but he will always return to his sinful ways and unbelief. The ancient Israelites were unregenerate just like their neighbors. For this reason a man must be born again to see the kingdom of God.
What shall I do?
The only thing that I can do is warn of the destruction to come and point people to Jesus Christ for salvation from the penalty of sin. I cannot give anyone a new heart; however, I can pray to the Lord, asking him to change hearts, I can also impart knowledge to others. Therefore, I shall pray that the Lord changes hearts, preach the law (The Ten Commandments) to bring the knowledge of sin and preach faith in Jesus Christ for salvation.