The Psalms, in Orthodox thinking, are often represented as being “the mind of Christ.”
They are read from this perspective – as prophecies of Christ as well as helping us to see the world as Christ sees the world. It is precisely because they can be read in this way that they became so popular in the worship of the early Church. Jean Danielou notes that it is the messianic nature of the Psalms which made their appropriation by the early Church so complete. They became the basis for early Christian worship because they were read as being primarily messianic. Their historic value was not their main appeal to the early Christians. It is not their Jewish nature which gave them their authority; rather it was their messianic nature.
“But the fact is this: the whole of ancient tradition concerning the liturgical use of the Psalms rests on their messianic significance. For one thing, it is the significance which constituted all their value for the primitive Christian community. It adopted the Psalms, not because of their religious value nor because of their inspired character, but only because it thought that they were concerned with Christ. Their whole use in the Church rests, therefore, on a messianic meaning. If this is no longer their real meaning, their liturgical use is based only on an accommodated symbolism and loses all dogmatic significance. This use is of value only to the extent to which the christological interpretation is not something added, but truly corresponds to their literal significance.” (THE BIBLE AND THE LITURGY, p 315)
In other words, their use by the early Christians was not because David wrote them, nor was their meaning best discovered through researching their original historical context and purpose. They were valuable because for the early Christians the Psalms literally were about Christ. Whatever their original context was or their author’s intentions were, the early Christians understood them to be about Christ – they revealed Christ and were revealed by Christ. They were chanted and sung by the early Christians because they brought the believer into a relationship with Christ.
Jesus said: “These are my words which I spoke to you, while I was still with you, that everything written about me in … the psalms must be fulfilled.” (Luke 24:43)