The Psalter speaks the universal language of the soul. ‘The Book of Psalms’, wrote Prothero, ‘contains the whole music of the heart of man.’ Again, echoing a phrase used by Athanasius and later by Calvin, it is ‘a mirror in which each man sees the motions of his own soul’. Its theology is rich and full. It reveals a God who is both the Creator of the world and the redeemer of his people. Moreover, he sustains what he has created and shepherds whom he has redeemed. It is this past and present activity of God, in nature and in grace, which provides the constant theme for the psalmists’ praise. Jehovah is not like dead, dumb idols; he is the living God, the Most High God, eternal and omnipresent. He is king. He reigns over the elements and over the nations. He is also a constant refuge, a fortress, and a strong tower where his people may find safety. He has entered into a covenant with them, and he is faithful to his covenant. He has given them his law, and expects them to be faithful to it. But, in contrast to God’s eternity and greatness, man’s life is transitory and his size diminutive. Further, he is sinful, and liable to sickness, persecution and death. He needs to cry to God for the forgiveness of his sins and for deliverance from all evil. Then one day God will send his Messiah to fulfil the ideals of kingship set forth in the royal psalms and of innocent suffering set forth in the passion psalms. It would be necessary for the Christ to suffer and to enter into his glory (Lk. 24:26).
–From “The Canticles and Selected Psalms” (London: Hodder and Stoughton, 1966), p. 12.