This Psalm calls down curses upon those who have opposed the Psalmist.
See verses 1-8, 26.

Sometimes we hear that these prayers were acceptable in the Old Testament but they are not acceptable today.
In the OT God's people were encouraged to love their enemies- Exodus 23:4-5; Prov. 25:21-22.
In the OT God's people were forbidden from taking personal vengeance- Proverbs 20:22; 24:29.
In the NT we find God's people calling down curses upon the wicked- I Cor. 16:22; Galatians 1:8-9; 5:12; Rev. 6:9-10.
In the NT we find rejoicing at the fall of evil and wicked people- Rev. 18:20; 19:1-6

This is not an effort to eliminate Matthew 5:43-48; Luke 6:27-36; Luke 23:34, or Acts 7:59-60 from the Bible. It is an effort to say that prayers of judgement also have their place.

These prayers show us
That evil is real- Isaiah 5:20- and that we must be outraged by evil- Psalm 119:104, 128, 163.
These prayers do not encourage personal vengeance but they leave things in the hand of God- Psalm 35:13-14; II Timothy 4:14.
The prayers are motivated by a desire that God be glorified- Psalm 58:11; 59:13.

Contend, O LORD, with those who contend with me. Fight against those who fight against me.

In this Psalm David describes how he was mistreated, lied about, pursued by wicked people.

Frequently through the Psalm David will affirm his innocence- vs. 7, 7, 11, 13-14,

He calls on God to rescue him and to judge those who are mistreating him- vs. 3, 4-8, 26

He calls on God to bring the same kind of judgment upon the wicked that they are bringing upon him. We sometimes call this lex talionis. Lex talionis is literally law of the tooth. We used it to speak of how in God's justice the punishment often fits the crime.- vs. 7-8.

This psalm speaks of the fear- vs. 4- troubles- vs. 6, 17- afflictions - vs. 19- of the righteous. 

This psalm speaks of the LORD delivering and rescuing His people from afflictions- vs. 4, 6, 17, 19. 

Psalm 34 speaks of God protecting HIs people- vs. 7, 9, 10, 15, 20, 22.

This psalm speaks of God judging the wicked- vs. 16, 21.

Psalm 34:20 is applied to Christ's death on the cross- John 19:36 and context.  John 19:36 also applies to Jesus fulfilling the picture of the Passover Lamb in Exodus 12:46; Numbers 9:12. But Jesus also fulfills the picture of the righteous sufferer in the Psalms. 

The above idea stretches the idea of God delivering the righteous. If we do not see it fulfilled in this life, we shall see it in the resurrection.

I Peter 2:3 alludes to Psalm 34:8 and I Peter 3:10-12 quotes Psalm 34:12-16. The righteous people who received this epistle were experiencing troubles, fears, and afflictions. Psalm 34 gives them assurance that ultimately God would deliver the righteous from all of these. 

This Psalm praises God

33:1-5 Sing to Him a new song and praise Him you who are righteous

33:6-9 The LORD as Creator- Let all stand in awe of Him

33:10-12 The counsel and plans of the nations are thwarted but God's counsel and plans stand

33:13-15 The LORD sees all people and all their works

33:16-17 Victory belongs to the LORD
Kings, warriors, and horses cannot bring victory by their own strength but the LORD is source of our strength

33:18-19 The eyes of the LORD are upon us and rescue us from disaster

33:20-22 All of these words are to encourage us to trust in the LORD and hope in Him

How Jesus fulfills Psalm 33?
Jesus is Creator- John 1:1-3, 10; Col. 1:15-17; Hebrews 1:1-2

Jesus is the Word- John 1:1-3, 14; Revelation 19:13-14

The death and resurrection of Jesus are the ultimate demonstration of the LORD thwarting the plans of the nations and accomplishing His will- Psalm 2:1-3; Acts 4:25-28; compare its language with Psalm 33:10-11.

Jesus gives us a new song- Revelation 5:9; 14:3. 

This psalm describes  David's struggle with unconfessed sin and then the joys of forgiveness when he humbled himself before God.
1. The burden of sin- 32:3-5
His bones have wasted away and he is groaning- 32:3
His pain is perpetual- 32:3 "all day long" and 32:4 "Day and night"
The hand of the LORD is heavy against him- Ruth 1:13; I Sam. 5:6, 7, 9. The hand of the LORD that David looked to in 31:5, 15 is now pressing against him heavily. This is not God's fault but it is David.
His strength is dried up- 32:4
Are you carrying this heavy burden?

2. The blessings of forgiveness- 32:1-2
Three different terms for evil are used- transgression, sin, and iniquity
Three different terms for forgiveness are used- forgiven, covered, not imputed or not counted
Three different terms for confession are used- acknowledged, did not hide, confessed
God is more willing to forgiven than we are to confess- 32:5

3. The mood changes at 32:6 and he calls on all to learn the lesson from this.
pray to God in a day when He may be found- 32:6
Do not be like the horse who has to be beaten to be kept on the right path- 32:9
Contrast the wicked- 32:10- and the righteous- 32:11. The righteous rejoice at God's salvation. 

The Psalm is quoted by Christ on the cross. Psalm 31:5 is quoted by Jesus in Luke 23:46. 
This does not mean that the psalm speaks exclusively of Jesus since 31:10 makes a reference to the writer's "iniquity"- NASB. Some versions have words like "misery" instead of "iniquity." The word "iniquity" is based on the Hebrew text and the word "misery" is based on the Greek translation of the OT. 

Notice some of the things that David experienced that Christ also experienced. 
They laid a net to trap him- vs. 4. The slandered him and plotted to kill him- vs. 13.
David was a "man of sorrows"- vs. 10 and was forsaken by those closest to him- vs. 11.
David experienced these things and was delivered from death. Jesus experienced all these things and He was crucified, but not even death stops the promises of God. God raised Jesus and provided salvation through Him. 

This psalm tells us God's anger is for a moment but His favor is for a lifetime- vs. 5.
God will turn our mourning into danger and give us garments of joy instead of sackcloth- vs.11
Judgement is not the final word for God's people
Exodus 34:6-7; Isaiah 54:7-10
Jesus fulfills the psalm in the greatest sense by HIs resurrection and He turns our grief to joy. 

The Power of God in the thunderstorm
The psalm speaks of the LORD 18 times and the "voice of the LORD" 7 times. 
The Canaanites believed that Baal controlled the storm and the lightning. But the things that psalms attributes to Baal, the Bible attributes to YHWH. 
The showdown between Elijah and the prophets of Baal is about who controls these the storm, the lightning, and the weath. 

29:1-2 A Call to Praise God

29:3-9 The glory of God in the thunderstorm

29:10-11 The LORD as King forever

Jesus fulfills Psalm 29
The "voice of the LORD"  could be tied with Jesus as the Word- John 1:1
The heavenly being- ESV- praising God in vs. 1-2 finds fulfillment in Luke 2:10-11.
Jesus demonstrates His control of the storm in Mark 4:35-41
Jesus walks on the water in Mark 6:45-52 and shows His control over the elements.
Jesus can turn water into wine- John 2:1-11. 

This psalm has been described as an individual lament or a psalm of thanksgiving or a royal psalm. 
 
 28:1-5 Petition
 
 28:6-9 Praise 
 
 Key words: Notice has "hear the voice of my supplication" in vs. 2 is picked up in vs. 6.
 The word "hands" is used to refer to David lifting his hands to God in vs. 2, the hands of the wicked in vs. 4, and the work of God's hands in vs. 5.
 The word "bless" is used in vs. 6 of David blessing God and in vs. 9 begging God to bless David.
 In vs. 2 David "lifted up" his hands to God and in vs. 9 the LORD is carrying or "lifting" HIs people. 

The LORD is my light and my salvation, whom shall I fear? These bold words introduce this psalm. 
27:1-6 sound more like a psalm of confidence or praise 
27:7-14 sound more like an individual lament as David pours out his problems to God
Some have suggested that these were originally two different psalms. However, a common vocabulary ties the portions of this psalm together: "God of my salvation" vs. 1, 9; "adversaries" or "foes" in vs. 2, 12; "heart" in vs. 3, 8, 14; "seek" in . 4, 8, 9. These are some of the common links in the psalm. 

Two verses that stand out to me are verses 4, 10.
In vs. 4 he desires to be in the house of the LORD more than he desires anything else.
In vs. 10 he asserts that the LORD will not forsake him. The LORD is more reliable than the most certain cases of human love. 
So he affirms his desire not to forsake God on the basis of his knowledge that God will not forsake him.