The Stabat Mater is not a mass. It is a telling of Jesus' crucifixion from His mother Mary's perspective. The text is not biblical and came into being in the 13th century. I find it very interesting that a Lutheran church is presenting this particular concert, beautiful though the music is, commemorating their anniversary. The Lutheran church's founder, Martin Luther, severed ties with the Catholic church for reasons such as these non-Biblical texts and dogmas.