Like the various types of biblical text, ancient liturgies differed according to the region where they were in use. Naturally they influenced one another. The liturgy of Jerusalem or Rome or Constantinople or Alexandria would impress visitors from other churches, who would then introduce at home a form of prayer akin to or identical with what they had witnessed on their pilgrimage. The church at Jerusalem seems to have exercised particularly potent influence, as one can see in the pilgrim diary of the lady Egeria from the Atlantic coast of Spain or Gaul, who recorded in colloquial Latin a succession of visits in about 384, including Euphemia's shrine at Chalcedon, Thecla's at Seleucia (Isauria), Ephesus for St John, and above all the ceremonies at Jerusalem. Pope Innocent I had to invoke Petrine authority to dissuade churches in central and southern (suburbicarian) Italy, such as Gubbio, from following the use of Milan. The kiss of peace was normally a prelude to the offertory, but at Rome Innocent had it before the actual communion, the text of Matt. 5: 24 being influential. Augustine warned against the introduction of too many ceremonies, and especially the borrowing of customs seen abroad (ep. 54. 3). He thought it caused confusion to the faithful. At Carthage he had to defend a psalm chanted either at the offering of bread and wine by the people or during the distribution, which encountered wrath from a conservative and influential layman (Retr. 2. 11). The diversity and the mutual influence can be illustrated from the fact that the Sanctus, which by the age of Constantine had a secure place in the eucharistic prayer in Syria and Palestine, was used in few western churches before 400. It was to become universal in the west until Calvinist worship in the sixteenth century.
Despite regional variety, it is surprising to discover how much the different forms of worship had in common. Psalms and readings were very ancient, but all churches seem to have continued with them and each region developed its own lectionary of scripture lessons, in many places (not all) allowing also the reading of Acts of Martyrs on the appropriate anniversaries. There was a general sensitivity and aversion to the reading of apocryphal texts in the lectionary, though the evidence shows that these were widely known and therefore read in private or in small groups, as with the followers of Priscillian of Ávila who was an enthusiast for non-canonical books; for him