What does Psalm 9:18 mean?

Contrary to the horrific fate of the wicked (Psalm 9:17), those who are needy won't be abandoned by God or left in a state of eternal death. This verse forms a deliberate contrast to verse 17. Verse 17 refers to the nations that forget God, but this statement speaks of the needy who will not be forgotten. Both aspects of the contrast matter here: those whom God "remembers" are those who follow and honor Him. The wealthy unbelievers will still be held accountable, while even the poor who believe will be redeemed.

It is possible for the needy to feel forgotten when material struggles arise. But ultimately, God provides for His people, even when they struggle. He will come to their assistance, always, in spiritual ways, and often in material ways, as well. Furthermore, the poor who believe in Christ hope for a better life, and someday they will have it (Romans 8:28–30). The fulfillment of these aspirations awaits the establishment of Messiah's kingdom on earth. Jesus promised, "Blessed are you who are poor, for yours is the kingdom of God" (Luke 6:20). In the kingdom age everyone will enjoy security and property rights. No one will be poor or needy. Micah 4:4 promises, "They shall sit every man under his vine and under his fig tree, and no one shall make them afraid, for the mouth of the LORD of hosts has spoken."