“Offer right sacrifices, and put your trust in the LORD.” —Psalm 4:5
David calls for his enemies, those who are trying to shame his honor (Psalm 4:2), to offer right sacrifices. I believe the implications is that they were offering sacrifices—to YHWH! But, they were not right. Why? Their sacrifices made in the temple and according to the law, were expressions of rebellion and idolatry.
I also take the “many” referred to in v. 6 to be these same enemies. David goes on to contrast himself with them in v. 7.
“There are many who say, ‘Who will show us some good? Lift up the light of your face upon us, O Lord!’ You have put more joy in my heart than they have when their grain and wine abound.
Why were these men—Jews, not Gentiles—unhappy with David, God’s anointed? They wanted “good,” they wanted it as it came from YHWH invoking the Aaronic blessing (Numbers 6:22-27). They were prosperity theologians. They wanted the good, they would even render up service to God in seeking it, but they despised God’s king. They wanted God’s goods, but not His “son” (Psalm 2:7). David, in contrast, delights in God Himself. David is opposed, yet finds superior joy in God Himself. His enemies lack some good, and are disgusted with God’s king. Who is worshipping God?
These men treated sacrifices like quarters and God as a vending machine to dispense the goods they want. Likewise, much worship, in Christian congregations, is a rebellious act of treason against King Jesus (cf. Isaiah 1:12–20). You cannot by much sacrifice wield God to bless your unrighteous rebellion.