In the spiritual way of life of mankind, the Guru has emphasised that there should not be any desecration of Kes (hair), i.e., cutting or trimming it by any means and according to the Guru’s holy advice is a cardinal sin. Any Sikh, who violates the divine instructions of the Guru in this respect, has to get initiated with Amrit (Divine Nectar) again after accepting the punishment from the ‘Five Beloved Ones’, otherwise he would develop animal instincts and by committing sins, would go to hell. All the Prophets and divine persons used to keep their hair long, which shows that hair is correlated with spirituality. As such, the Guru has emphasised that Sikhs should not cut their hair if they want to get pleasure of the Divine and attain self-realisation. The Almighty Lord is the Creator of the whole world. Persons, who have full love and devotion for the All Pervading Divine Lord (Akal Purakh), naturally pay full respect to His Creation and bounties bestowed upon not only the human beings, but also other creatures.
After seeing in human beings the physical attributes of God, the first Divine Master Guru Nanak Dev enunciates in the Hymn the praises of His beautiful attributes thus:
ਤੇਰੇ ਬੰਕੇ ਲੋਇਣ ਦੰਤ ਰੀਸਾਲਾ ॥ ਸੋਹਣੇ ਨਕ ਜਿਨ ਲੰਮੜੇ ਵਾਲਾ ॥
T-ai-rai bank-ai lo-e-nh dantt reesaalaa. Sohnh-ai nakk jinn lammrhai vaalaa. (567)
(O Divine Master in the form of humanity! Your eyes are wondrous and your teeth and nose are wonderful with the attribute of long hair.)
~ Content Source: Sikh Faith book, written by Baba Iqbal Singh Ji