What does Psalm chapter 43 mean?

Many Hebrew manuscripts join Psalm 42 and Psalm 43 as a single work. It's possible they were separated, at some point, for unknown reasons. The themes of Psalm 43 echo those of the prior song. Overall, the psalmist honestly expresses frustration with his suffering. Yet he makes a conscious effort to remember God's faithfulness and resolves to look to the future with hope.

The psalm opens with an appeal for justice. Because he is being oppressed and slandered, the writer asks why God has not yet come to the rescue. This is followed by a request echoing a prior desire to return to a place of worship (Psalm 42:4). The psalmist refers to God's truth, and His light, which are common themes in the Bible. The appeal ends on a hopeful note, with the assumption that the writer will be able to worship God in the temple once again (Psalm 43:1–4).

The final verse of this psalm is the exact phrase used twice in the prior song (Psalm 42:5, 11). This is a statement, poetically phrased as a question whose answer should be obvious. It's natural to be tempted towards despair and discouragement. Despite our feelings, we know God is faithful and that He will vindicate His people, eventually. For that reason, we can be encouraged to put all our trust in the Lord (Psalm 43:5).