He refused military service in 1926 and was therefore repeatedly imprisoned between 1929 and 1931. The motives of Pekurinen were not religious or political. He was the leader of Finnish pacifist movement. The Lapua movement harassed him continuosly. An international petition on his behalf was sent to the defense minister Juho Niukkanen in 1930. 60 members of the British Parliament, and notable persons such as Albert Einstein, Henri Barbusse and H. G. Wells had signed the petition. April the 14th in 1931 "Lex Pekurinen", the first alternate service law of Finland, was passed. However, the law covered only peacetime.
At the beginning of the Winter War Pekurinen was convicted again, for three years. In the early attack phase of the Continuation War, in Autumun 1941, he was released and sent to the front. Pekurinen refused to wear uniform or carry arms, and was therefore executed in Suomussalmi. The order to kill Pekurinen was given by captain Pentti Valkonen. The first two soldiers who were ordered to shoot him refused.
After the war, an investigation of his killing was started, but never finished. For more than 50 years his fate remained unknown, but in 1998 a book describing his life was written by Erno Paasilinna: Courage: the life and execution of Arndt Pekurinen.
His motto was inspired by Jonathan Swift:
"As people are not eaten, butchering them is of no use."
(Kun ihmisiä ei syödä, on niitä turha teurastaa.)