The first distinguishing feature of the biblical psalms is the direct, personal approach to God. There are no intermediaries, human or celestial, no being or beings who facilitate the ascension of prayer to the divine realm. Nor is there any notion of angelic intercession or influence. Then there is the unqualified conviction that prayer is heard, that the Deity is approachable and responsive to the pleas of humankind, though not necessarily immediately or always favorably.
Nahum Sarna, On the Book of Psalms: Exploring the Prayers of Ancient Israel, 206.