The late Christian mystic and writer Evelyn Underhill had this to say about war:
To defeat the power of evil by the health-giving power of love and thus open a channel for the inflow of the creative grace of God is therefore the only struggle in which the realistic Christian can take part. No retaliation. No revenge, national or personal. No “defensive wars” – i.e., destroying our brother to prevent him from destroying us. “Fear not him that can kill the body” says the Church – or so at least the Church ought to say. Yet armament factories working full time announce to the world that we do fear him very much indeed; and are determined, if it comes to the point, to kill his body before he can kill ours. This attitude is one with which the Christian Church must never come to terms; for questions of expediency, practicality, national prestige and national
safety do not as such concern her. All these derive from human egotism and human fear. Her single business is to apply everywhere
and at all times the law of charity; and so bring the will of man, whether national or individual, into harmony with the Will of God.
From ‘The Church and War’. Written in 1940 for the Anglican Pacifist Fellowship.