In Psalm 17, King David cries out to God for deliverance from the enemies that surrounded him even though he had done nothing wrong. In contrast to his enemies, who had nothing to look forward to beyond this life, David rejoiced in God, who would satisfy him in this life and the next.
In Psalm 14, we discover that it is a foolish thing to create our own ideas of God in our heads. The biblical view of God is one that acknowledges his holiness and our inability to meet his standards as well as one that sees his grace offered to anyone who repents and believes.
In Psalm 6, David cries out to God for deliverance from an illness. Thought he eventually experiences deliverance, we should give ourselves permission to express our lament in the face of deliverance that will certainly come, whether in this life or the next.