The psalmist asks two rhetorical questions in verse one. The questions make more sense as one reads through the conclusion of the psalm. The nations rebel and devise plots against the LORD and his anointed king, which are destined for failure (1). Why do they do such things? Good question. The psalmist infers that it makes no sense to do such things. The kings and rulers unite themselves against the LORD and his anointed king (2). The reason they do so is to, “tear off the shackles they’ve put on us! Let’s free ourselves from their ropes!” Sinful man hates to live in subjection to the one true God. It vexes his spirit to be accountable to God. Therefore, he fights it. He refuses to submit to God. In the context, the psalmist also includes the Davidic king as the earthly representative of God, to the psalmist it was likely Solomon, to us today we know it ultimately refers to Christ.
God is unimpressed by their proud rebellion because they are powerless against him (4). He speaks in anger to them (5). He declares that he has appointed his king in Jerusalem, his holy hill (6). God has done these things and there is none who can undo them.
The Davidic king speaks to the rebellious nations by informing them of God’s decree. God has chosen the Davidic king as his son (7). This is a relationship of proximity and intimacy. The king also informs the nations that God has promised the nations as an inheritance and the ends of the earth as his personal property (8). God has informed the king that he will rule the nations (9).
The psalmist warns the kings and rulers to be wise and submit to correction (10). They are to cease rebelling. They are to serve the LORD in fear and repent in terror (11). God is able to wipe them out in an instant. They should given genuine homage to the king or he will become angry in a moment and wipe them out (12). Their rebellion will result in their death unless they repent.
The psalmist concludes by declaring that all who take refuge in him are blessed (12b). At the very least this refers to the Davidic king and ultimately to the LORD. The totality of Scripture indicates that it is ultimately Christ in whom believers are blessed to take refuge.
Consider this, the nations are still rebelling. The kings and rulers are still uniting and plotting against the LORD and his Anointed King, Jesus Christ. “Why do the nations rebel? Why are the countries devising plots that will fail?”