Psalm 95 is read on the third Sunday in Lent in churches following the Revised Common Lectionary.
This Psalm starts out as a psalm of gathering and praise. This praise takes the form of singing and shouting. It leads to bowing down and kneeling. So with voice and self-abasing body language the people acknowledge their God as the highest God, their maker, who also made earth, mountains, and seas. The praise sounds boisterous, as though the aim was to rock the place of worship.
Verse 7 introduces an abrupt change in mood.
If only you would listen to God.
Amidst all the joyful noise you are making and all the worshiping and praising, are you listening to God? It is not enough to be loud and enthusiastic. You also need to listen and soberly evaluate yourselves.
The psalm brings up the Meribah/Massah incident. There are a couple of versions of this incident in the Torah. I believe the psalm is primarily referencing the account in Numbers 20:2 ff. This is because Moses and Aaron in Numbers 2:6 prostrate themselves before God and Psalm 95 has just said that the worshiping congregation prostrated themselves before God. Also Numbers refers to the people there as rebels just as Psalm 95 does.
Lacking food and water on the trek from Egypt, the people had rebelled. Exodus says Moses was in fear for his life. Psalm 95 attributes this rebellion to their failure to remember the works (opening the sea, quail, manna and so forth) God had already done. What have you done for us lately?
So the last verses of Psalm 95 contain a prophetic warning. Don’t be like your ancestors or God will write off your generation just has he wrote off the wilderness generation.
This Psalm fits with the period during or after the exile in Babylon. The popular interpretation of why Jerusalem had fallen was that God had become fed up with religious and social disobedience of Israel and her kings. Thus a psalm of praise needed to have an element of warning in it as well.
It is not enough to engage in loud worship or even to fall on your face before God. You also have to obey.
A lot of Christians ignore Lent but celebrate Easter. They want to get to the lilies and the trumpets. The more somber notes of Lent don’t appeal to them. But Psalm 95 wants God’s people to combine their praise with repentance and obedience. This is a fitting theme for Lent.