
The Psalms are mostly imagery and metaphors, like most poems or songs. Mainly, the five themes are Sovereignty, Hierarchy, Law, Sanctions, and Future.
In verses about Sovereignty, the Psalms say how God is still above all, but we have are own will and can choose to disobey him. In Psalm 18 verse 1-3, David writes that the Lord is his rock and his fortress, and God will deliver him from his enemies, who have chosen to disobey God so they will be smited.
Hierarchy mainly focuses on how the kings of the earth are no match for the king of heaven and that the earthly ruler’s dominion is not theirs but the Lord’s since he created it. David explains in Psalm 2 that the kings of the earth will take counsel against God, but God will sit in heaven and laugh at them. Instead, David instructs them to be wise, serve the Lord with fear, and kiss the son, lest he be angry.
Another important theme is Law. In verse 1 it states that he who has delight in the Law will bring forth good fruit and not wither. Wickedness will be judged by God and will come to an end. David proclaims his defense in God, who will save the upright in heart and Law. Emphasizing his point, David again states that the only people who are worthy to stand in the tabernacle are the ones who walk upright, worketh righteousness, speaketh truth, that backbiteth not with his tongue, nor do evil to their neighbor. Subsequently, the only people who follow God’s Law will enter heaven.
In addition, David says we have a code with God, and if we break it, there will be sanctions for us. Defending himself, David notes that he has not sat with vain persons and he hates the congregation of evil and will not sit with the wicked. Washing his hands with innocence, he will compass the Lord’s altar and ask the Lord to gather not his soul with sinners because they have broken God’s sanctions. Those who give themselves to wine and debauchery will not be able to grow their corn due to their unrighteousness.
The future is shown multiple times in the Psalms, mostly in examples of what will happen to the wicked. Psalm 9 tells that the sinners have ruined cities, and the destruction that the wicked have done will come to an end. David says the Lord’s name will endure forever and all nations shall call him blessed. The overall message of the Psalms is that God is sovereign: he rules men, even the rulers of the earth, he rules in terms of Law, he brings sanctions, positive and negative, and his inheritance will only be granted to those who keep the law.