It reminds us that God is not bound to offer grace to the disbelieving rebels, although He has done so time after time. It reminds us that God may also speak judgment to those who close their ears to His grace.
God is paying attention. God comes close to us, wants to be present with us, attends with us.
In our hurry to get through the forty days of Lent and to the celebration of Easter, this psalm slows us down. Yes, Resurrection Day will come but lest we forget to remember our need for resurrecting in the first place.