Church archives are not only a depository of important documents illustrating the formation and historical development of church communities, but also fulfil a spiritual mission. Attention is drawn to this in a Circular Letter to diocesan bishops entitled: The Pastoral Formation of Church Archives, issued by the Pontifical Commission for the Cultural Heritage of the Church (Pontificia Commissione per i Beni Culturali della Chiesa) on February 2, 1997. This little-known document in Polish was published only in 2010, translated by Fr. Rafał Rybacki commissioned by the Archdiocesan Archives in Poznań on the occasion of the 85th anniversary of its establishment 1925–2010. It emphasized that church archives are “places of memory of Christian communities” and “cultural assets of primary importance”. Their specificity lies in the fact that they commemorate the journey of the Church and the manifestations of its presence in the world. By preserving authentic documentation that was spontaneously created as a result of the relationship between people and events, church archives commemorate the mission of Christ himself, who leads his Church along human paths, cultivate the memory of the life of the Church and are a testimony to the existing sense of Tradition. The document The Pastoral Formation of Church Archives emphasizes that church archives, as Pope Paul VI use store traces of the transitus Domini, i.e. the Lord’s passage through this world.