What led Guru Gobind Singh to modify Sikhism and require the Five “K’s” as an essential part of the faith?

Respected Tejpal ji,
Waheguru ji ka Khalsa, Waheguru ji ki Fateh!

In reply to your question, ‘what led Guru Gobind Singh to modify Sikhism and require the Five K’s as an essential part of the Sikh faith?’, the undersigned wants to say that there is a misconception that Tenth Guru Person Guru Gobind Singh Sahib modified Sikhism whereas the fact is that he only took the process, started by First Guru Person Guru Nanak Sahib, to a conclusion and closed the process of living Guru Persons and pronounced Guru Granth Sahib (Shabad Guru) as ever living Guru of Sikhs.

In support of the above statement, the undersigned wants to say that the fight against rituals, karamkands, oppression, tyranny, persecution, atrocity and cruelty started when First Guru Person Guru Nanak Sahib didn’t agree to wear janeu, stayed with Bhai Lalo but didn’t agree to eat Malik Bhago’s food and stood before Babar, when he was killing innocent people.

Second Guru Person, Guru Angad Sahib stood before Humayun, when he pulled out his sword from the sheath to intimidate him. Third Guru Person Guru Amardas Sahib, asked Sikhs to stop the practice of sati, veils by ladies and hit the caste system, when he laid down that whosoever wants to see him must eat langar like any ordinary person. Even Akbar had to do it.

Fourth Guru Person Guru Ramdas introduced the process of Lavan and with this the necessity of Brahmin, for marriage ceremony ended.

About subsequent Guru Persons, the undersigned is not writing any details as all of us know that how they stood against oppression, tyranny, persecution, atrocity and cruelty without losing spiritual equipoise (ਆਤਮਿਕ ਅਡੋਲਤਾ). It is said that the steel of Kirpan used by Tenth Guru Person Guru Gobind Singh Sahib against oppression, tyranny, persecution, atrocity and cruelty, was prepared by First Guru Person Guru Nanak Sahib.

All the Guru Sahiban taught Sikhs to rise above the fright of physical death.Please be kind to read the following stanza from a Shabad of Kabir ji at Panna 654 of Guru Granth Sahib in which he is guiding us to rise above the fright of death:-

ਪਰਿਓ ਕਾਲੁ ਸਭੈ ਜਗ ਊਪਰ ਮਾਹਿ ਲਿਖੇ ਭ੍ਰਮ ਗਿਆਨੀ ॥ ਕਹੁ ਕਬੀਰ ਜਨ ਭਏ ਖਾਲਸੇ ਪ੍ਰੇਮ ਭਗਤਿ ਜਿਹ ਜਾਨੀ ॥੪॥੩॥ {ਪੰਨਾ 654}
ਅਰਥ: ਸਾਰੇ ਜਗਤ ਉੱਤੇ ਕਾਲ ਦਾ ਸਹਿਮ ਪਿਆ ਹੋਇਆ ਹੈ, ਭਰਮੀ ਗਿਆਨੀ ਭੀ ਉਸੇ ਹੀ ਲੇਖੇ ਵਿਚ ਲਿਖੇ ਗਏ ਹਨ (ਉਹ ਭੀ ਮੌਤ ਦੇ ਸਹਿਮ ਵਿਚ ਹੀ ਹਨ) । ਹੇ ਕਬੀਰ! ਆਖ-ਜਿਨ੍ਹਾਂ ਮਨੁੱਖਾਂ ਨੇ ਪ੍ਰੇਮਾ-ਭਗਤੀ ਕਰਨੀ ਸਮਝ ਲਈ ਹੈ ਉਹ (ਮੌਤ ਦੇ ਸਹਿਮ ਤੋਂ) ਆਜ਼ਾਦ ਹੋ ਗਏ ਹਨ।੪।੩।

The Sikh, who is a student, by imbibing the teachings of Guru Granth Sahib, has to rise above the fright of death and become Khalsa i.e. Akalpurakh’s own. Perhaps, you would be aware that Khalsa is a Persian word, which means King’s own land.

Once the Sikh become Akalpurakh’s own then Akalpurakh will always be with him and he will not do anything which will lead to his Spiritual Death (ਆਤਮਿਕ ਮੌਤ). In a way, the Sikh has to live a disciplined life, as per the teachings of Guru Granth Sahib.

The practice of giving Pahul and Five K’s was started by Tenth Guru Person Guru Gobind Singh Sahib on the Vaisakhi day of 1699 to prepare a disciplined force of ‘Sant Sipahis (ਸੰਤ ਸਿਪਾਹੀ)’, so as to fight against all kind of oppression, tyranny, persecution, atrocity and cruelty.This disciplined force of Sant Sipahis came to be known as Khalsa i.e. Akalpurakh’s own, who rose above the fright of death and fought all kind of oppression, tyranny, persecution, atrocity and cruelty in the past and continue to do so.

In view of the position stated above, you can very well see that the Tenth Guru Person Guru Gobind Singh Sahib didn’t modify the Sikhism but took the process started by First Guru Person Guru Nanak Sahib to a conclusion.

Hope this helps. If you have any further questions, please do ask. If there are any shortcomings please do point out the same for improvement in future.

Regards,
Your Brother