The Church offers us different prayers that we can say every day of the week for the faithful departed. These are especially useful for offering a novena on behalf of the dead, or for praying during those seasons of the year (November, in the Western Church; Lent, in the Eastern Church) designated by the Church as times of fervent prayer for the dead.
This prayer is offered on Fridays for the souls of the faithful departed.
Friday Prayer for the Faithful Departed
O Lord God omnipotent, I beseech Thee by the Precious Blood which Jesus Thy divine Son did shed this day upon the tree of the Cross, especially from His sacred Hands and Feet, deliver the souls in purgatory, and particularly that soul for whom I am most bound to pray, in order that I may not be the cause which hinders Thee from admitting it quickly to the possession of Thy glory where it may praise Thee and bless Thee for evermore. Amen.