The Psalmist prayed psalms that were relevant to his own circumstances; so why do I pray those same psalms when my circumstances may be different to his?

In his letter to Marcellinus, St. Athanasius the Apostolic explains that the true believer finds the psalms familiar to him because his circumstances are in fact very similar to the circumstances of those who wrote the Psalms. He says in this letter, “There is also this astonishing thing in the Psalms … he who takes up this book—the Psalter—goes through the prophecies about the Savior, as is customary in other Scriptures, with admiration and adoration, but the other psalms he recognizes as being his own words. And the one who hears is deeply moved, as though he himself were speaking, and is affected by the words of the songs, as if they were his own songs …

“And it seems to me that these words become like a mirror to the person singing them, so that he might perceive himself and the emotions of his soul, and thus affected, he might recite them. For in fact he who hears the one reading receives the song that is recited as being about him, and either, when he is convicted by his conscience, being pierced, he will repent, or hearing of the hope that resides in God, and of the other succor available to believers— how this kind of grace exists for him—he exults and begins to give thanks to God … on the whole, each psalm is both spoken and composed by the Spirit so that in these same words, as was said earlier, the stirrings of our souls might be grasped, and all of them be said as concerning us, and the same issue from us as our own words … All this is to prevent falling into impiety on the part of the one who speaks strictly according to such phrases. For not only because of deeds, but also because of idle speech, we are obliged to render an account to the Judge.”¹¹⁴