The Psalmist repeatedly shows faith in God throughout this psalm. The only solid foundation is God; the wise person does not build on sand, or the winds and floods will destroy the house (Mt 7:24ff). This psalm has a peaceful confidence that we often miss in many others, which instead feature almost frantic appeals. In the Psalter, we can usually find a prayer that fits our moods.
Only God can be the rock, stronghold, and fortress (3, 7, 8, 9) where human life can be supported. Human beings have a choice: to rely on their own power or divine power, to trust in riches or in God. Serving both God and money is impossible (cf. Mt 6:19, 24). You must choose to trust either in God or wealth: see 1 Timothy 6:17; James 4:13-14; 5:1-6. If we want to be messengers of trust, we need to speak not only of ideas but also of the experience of God as a fortress and refuge.
The Psalms are prayers from people who are constantly struggling and suffering violence. Look at the television news, and the violence in the world will be clear enough for us to pray this evening—the prayer of a real world trying to survive.