The first known attempts to bring Christianity to the Sámi began as early as the 14th century.
We dont know if they had any great effect, but some influences may be traced in later traditions.
In east Finnmark for example the Sámi had many fast days in the early 18th century. This probably comes from catholic times. Women in particular had to fast on the eve of the Feast of the Annunciation on 25th March, so that all their children would behave properly. If the fast was not kept, the passe alma (holy people or angels) would come and torment them.
Christian elements also made their way onto the drum; for example we find figures symbolising church, cathedral, the holy trinity, Mary, St. Anne and the devil (see Anders Poulsens drum).
The east Sámi were converted by the Russians and placed under the Russian orthodox church during the course of the 16th century.
Hansen, Lars Ivar og Bjørnar Olsen, 2004: Samenes historie.
Pollan, Brita, 1993: Samiske sjamaner: Religion og helbredelse.
Noaiden i samisk tradisjon