Psalm 78 is God's dealings with a rebellious nation. Verses 36-41 state, "Nevertheless they did flatter him with their mouth, and they lied unto him with their tongues. v.36
For their heart was not right with him, neither were they stedfast in his covenant. v.37
But he, being full of compassion, forgave their iniquity, and destroyed them not: yea, many a time turned he his anger away, and did not stir up all his wrath. v.38
For he remembered that they were but flesh; a wind that passeth away, and cometh not again. v.39
How oft did they provoke him in the wilderness, and grieve him in the desert! v.40
Yea, they turned back and tempted God, and limited the Holy One of Israel." v.41
Here we see a nation that said all the right things, but their heart was not right with God. Because of this, they ultimately turned back and tempted God, and limited what he could do. This entire Psalm represents a nation with unbelief.
God bless you,