It is likely Christianity in Scotland was not too far behind the rest of the British Isles, but the earliest surviving churches date to the 11th century, or later and excavated examples do not appear to date much earlier. But when it comes to evidence of the earliest Christian influences in Scotland scholars don’t have quite as many reliable resources as in other parts of Europe. The timeline for the Christianization of Gaul is fairly well documented starting in the 4th century. There is also there is broad agreement that St Patrick was active as a missionary in Ireland during the second half of the 5th century. St. Bede supplied a brief account of Christianity in Roman Britain, although recorded in the 8th century, it seems based on earlier accounts.
St. Columba and St. Ninian are traditionally considered the “apostles” of Scotland. But some scholars seem to consider them more useful for studying their 7th and 8th century motives, or attitudes than for accurate accounts of historical events. But there are tidbits within these that suggest that there may have been Christian influences or contacts by the Late Iron Age among the Picts as with some of the Britons. A curious bit of evidence is that Latin inscribed stones have been found in locations that suggest the spread north was not a steady flow. Rather, there may have been pockets of influence by the 5th century that were well beyond the walls of Roman settlements.
But more recent examinations of cemeteries and burial practices may be starting to bring a little more light on the matter. One theory is that the appearance of group cemeteries with roughly over the course of AD 400 to 600 may reflect the growing influence of Christianity. An excavation of a cemetery near the Lundin Links Standing Stones in Fife, Scotland is one example that seems to coincide with this theory as far as the period. It consisted of 24 for bodies that were found with little or nothing in the way of grave goods compared to some pre-Christian sites and with the interred bodies arranged in a head to the west, feet to the east position as is said to be a Christian tradition. But as the paper that inspired this article mentions, the early church probably did not firmly dictate the way that people were buried prior to the Carolingian period (Late 8th century to the end of the 9th century). Therefore, it is still more data that needs to be collected to study the Christian influence of Scotland through burial practices