St Athanasios' Letter to Marcellinos In the first part of the Letter to Marcellinos, St Athanasios shows how the book of Psalms summarises the whole of the Old Testament and foreshadows the New Testament. For the remainder of the letter, he demonstrates the rich variety of the Psalms and their applicability to our own spiritual life. St Athanasios writes: "It is possible for us, therefore, to find in the Psalter not only the reflection of our own soul's state, together with precept and example for all possible conditions, but also a fit form of words wherewith to please the Lord [...]