We have recently begun a new sermon series on Sunday mornings on Psalms 18-24, with Stephen previously having preached on the first 17 psalms (as well as 89 and 107) during evening services.
As we come to the Psalms, it is helpful to remember that they are ultimately The Songs of Jesus - breathed out by the Spirit of Christ, they speak about him, were sung by him on earth, and he still speaks through them today.
As O. Palmer Robertson asserts in his recent book on the psalms: ‘To understand these psalms in their fullest significance for the individual, they must first be appreciated for their role in speaking for God’s anointed servant, the messianic king’.
In his sermon on Psalm 18, Stephen noted that the Psalms actually shed light on the New Testament - a point made in the video clip below by Rev. Kenneth Stewart, who is currently our minister in Glasgow:
Therefore to focus largely on the situation of the human author of the Psalms is to miss the point. As Andrew Bonar comments on Psalm 18: ‘David’s circumstances, that made him suitable to be the vehicle of this divine communication, have moulded the language; but we are not to carry the allusion to his history too far’. Or in the words of Henry Law: ‘David soon disappears. Jesus Himself strides forth’. This is true whether the psalm is quoted in the New Testament and applied to Jesus or not. As Charles Spurgeon comments on Psalm 20: ‘It needs but a moment's reflection to perceive that this hymn of prayer is prophetical of our Lord Jesus’.
This point is well argued (contrary to some modern voices such as Don Carson and even the great Old Testament commentator Dale Ralph Davis) in a 2012 talk by Union Theological College Professor Michael McClenahan, summarised and linked to here.