Nearly all religions have used this idea of warfare. The beautiful teaching of the Bhagavad Gita is given in the context of the Battle of Kurukshetra. Although seen as a conflict between good and evil, the Lord Krishna tells Arjuna that he must fulfil his duty as a warrior and fight with the members of his family who are on the opposing side, even suggesting that their death is not of absolute importance as death is not final and their spirit will continue into another existence.
Baptised Sikhs see themselves as soldier disciples who wear a small knife, the kirpan under their clothing as a sign of their willingness to fight for truth and justice and to sacrifice their life for it. St Paul tells Christians to put on the armour of God and to arm themselves with righteousness in the fight against evil. And in Islam the idea of jihad is often in the news these days even though the great jihad is against the sinful self and not others.
All this fighting is about spiritual warfare and the fight is essentially an internal one between the good and evil that resides within all of us. Sometimes it spills over to seeing evil as external to us - sometimes in the form of another religion or way of life, sometimes the prevailing culture, sometimes individuals with different values and understandings of life. Then it can become violent and destructive. Even when it doesn't become destructive the notion of conflict suggests competition, struggle, polarisation between right and wrong, however it is perceived. It can lead to aggressive proselytisation, war, inquisitions, persecutions and even death and has done so in the past. Sometimes it has led religious groups like the Amish to withdraw from society, to live by their own standards, to set up a separate way of life which looks out of touch with modern society. Growing up I was taught that the Catholic Church was an ark tossed on a stormy sea but rather than defend ourselves against the storm should we not be learning to ride it and navigate our way through it? To do this we have to know it and understand how to relate to it.
So I wonder if we should change our narrative to avoid non-violent language. There's a story of a child who asked which side would win in the struggle between good and evil in his heart. The answer was 'the one you feed'. There's something to ponder in that methinks.