The Christian in Belgium or in England in 1914 should not have gone to war, in my opinion, since war is violently unchristian. He should have been Christian, that is, he should have lived in the spirit of Jesus Christ, returning good for evil, love for hatred, mercy for cruelty, kindness for atrocity. Even if his country had been conquered by Germany, he would have confronted the same situation which Jesus faced, and like Jesus he should have sought to get rid of the oppressor by other means than the sword.

Ch.6 p. 101-102 - The Sword or the Cross, Which Should be the Weapon of the Christian Militant? (1921)