This form almost certainly comes from the Norse "kirkja".
It actually comes all the way from a Greek word that means "the Lord's," short for a term for churches that means "the assembly of the Lord" or "the house of the Lord."
Certainly. But here I mean that the flow probably came through the Norse. The Scotts definitely got their term from the Norse. Since "Christianity gained a foothold in Finland during the 11th century. It was strengthened with growing Swedish influence in the 12th century and the Finnish "crusade" of Birger Jarl in the 13th century." [Wikipedia] and since the Swedes were often trading and plundering along the Finnish coast, then I strongly suspect that the current Finnish word came from the Swedish one, which comes from the same Germanic root as in English.
The only etymology I could find is: kirkko [from Germanic. Compare Estonian kirik, Karelian kirikkö, Lapland girku, Swedish kyrka] : church
It actually comes all the way from a Greek word that means "the Lord's," short for a term for churches that means "the assembly of the Lord" or "the house of the Lord."
http://www.etymonline.com/index.php?term=church
http://en.wikipedia.org/wiki/Christian_Church#Etymology
(Basis of knowledge: student of Biblical Greek, native speaker of English, sporadic student of various Germanic and Ugro-Altaic languages.)