Ishna ji
Now according to Macauliffe this whole section of bani is referring to Babar's invasion of Sayidipur. I get a very different interpretation if I read the angs as just stand alone Gurbani with no knowledge of the events (soldiers become the soldiers of Death, it becomes spiritual) but when I read it in the context of the historical events, then they become human soldiers in my mind. It's hard to explain. I think it's bad to read stories about how bania were composed because it clouds the true meanings I think. But I could be way off!
I can think of two reasons why it is important to know the history of events and how the banis were composed.
1. To be prepared, with research, to critique opinions, found on the Internet and in some academic circles, that challenge the authenticity of the banis themselves. Even challenge the authenticity of Sri Guru Granth Sahib Ji, with the plan of putting forward a Hindutva agenda/to destroy the identity of Sikhs. One famed example of that is the contemporary pressure to remove the banee of the Bhats and the Bhagats from Sri Guru Granth Sahib Ji. This is not the first time.
There is a systematic attack as we speak on Sri Guru Granth Sahib Ji coming from political quarters and it is powered by money and relentless need for control.
2. To understand that Guru Nanak's true message was moral and ethical as well as spiritual. Some believe that the fruition of Sikhi only came with Guru Gobind's Singh and his "warrior Sikh." This is a
complete myth, not based on evidence. The myth forgets that sant/sipahi is not a divisible as a concept. From the days of Guru Nanak Sikhs were to be both sant and sipahi or spiritual warriors. Before the martyrdom of Guru Arjan Dev their was little to no reason for Sikhs to take to the sword. After his martyrdom political realities required it. And knowing history gets us to the understanding that even when wielding the sword, Gurus from Hargobind to Gobind Singh did so reluctantly, and only with much consideration.
Guru Nanak Devji, Guru Amardasji the other Gurus were flesh and blood human beings who took an active interest in the world as it was in their times, to include all of the political and cultural outrages committed against humanity. They undertook pilgrimages, including Guru Teg Bahadur (perhaps the most mystical of Gurus) to raise the spiritual consciousness of the people, and to give them a moral and ethical center coming from dharma. They worked with their hands and hearts. Their "mystical organs" were not detached from the real world. Guru Harkrishan ji gave his life serving small pox victims. Guru Amar Das ji organized the Sikhs into geographical areas and appointed ministers, including women, to attend to their social and spiritual needs, Guru Har Rai is remembered as the "green" Guru. I could go on. Too many believe we wash our bad karma with seva, forgetting that "seva" for sikhs from the times of the Gurus was spirituality in action. Washing our karma with seva is selfishness. Living out the history of Sikhi through seva is the message of Gurbani in action.
Knowing the history Sri Guru Granth Sahib Ji
out of the ether of Brahminical "other worldliness." How could history take away the spirituality of Sri Guru Granth Sahib Ji? The bani for me mean so much more when I realize that Guru Nanak was not staring at his navel but was actually imprisoned with the captives of Babar, and suffered with them, when he could have taken his leave as a holy man. He did not do that and expressed righteous anger and deep compassion for the victims, which came from a place in dharma. Taken before Babar his spiritual message freed prisoners, corrected injustice.
Knowing how the shabads fit into a story of Guru Nanak's travels does change how we read them.... a real person is speaking from real experience. imho History makes the banis more spiritual not less given that the Gurus were faced with remarkable challenges in the face of great odds.