Religious diffusion is easier than some other countries in Denmark, the reason for this is because Denmark is quite a small country, as well as being completely surrounded by water, which is easier to navigate than the mountainous terrain. Christianity is the biggest religion within Denmark, and it originates in the Evangelical Lutheran Church of Denmark.
Language spreads similarly to religion, but possibly faster because sailors and traders have to communicate with each other. The people of Denmark mostly speak Danish which has German origins.