Sardar Raghbir Singh Bir was a Sikh businessman who used to live in Calcutta (Bengal). His family was originally from Lahore and his father Sardar Lehna Singh also was a very good Gurmukh. At first Bir jee got interested in Sikhi and he wrote the famous book Bandaginama on his spiritual experiences. In this book he writes that he used to dye and tie his beard, even though he knew it was a wrong practice. He did so at the order of his father who was not a religious person at that time.

Later on, when his father Sardar Lehna Singh got infected with many diseases including arthritis, he took up Sikhi to cure himself. He did so much Abhyaas of Gurbani and Naam that within a very short period he became perfectly healthy. Till his last breath, at the age of 85, he maintained the body of a 25 years old youth. He wrote a wonderful book on his experiences and is called Gurmukh Jeevan. He was a fanatic as far as not using worldly medicine is concerned. He considered himself as pure Atma and conducted his business as such. Once, he hurt his foot and he did all things opposite to what doctor suggested. He did not tie his foot with a bandage and deliberately exposed it to water (as opposed to doctor's advice) and still got healed. First of all he never got sick but if he ever did, he used to conduct his business as usual and ate normal as well. He totally used to reject the notion of disease because he believed that a disease cannot occur to Atma.

Once, Bir jee and Sardar jee (Lehna Singh jee) started talking about the Atma saroop of the Jeev. Bir jee questioned that if we were truly Atma, then why was there a need to sleep. At this Sardar jee agreed and then proved it by not sleeping for many days, and still not feeling any tiredness or fatigue. He used to do his regular work all day, and at night would come to the bedside of his son and all night do Naam Abhyaas.

Once a thought came to his mind that why should he use the mosquito net for protection from mosquitoes. He argued that the mosquitoes contained the same Parmatma Vaheguru as all of us and as such they should not bite him and hurt him. So he removed the net and also removed his shirt and slept with kachera only. The next morning his body was so badly bitten by the mosquitoes that there was not a part on his body that was unhurt. Sardar jee laughed it off saying that the reason why mosquitoes had hurt him was that he had some hidden hatred and negative feeling for them. Then he did Naam Abhyaas all day and kept affirming again and again that the mosquitoes were a roop of Vaheguru and that Vaheguru jee could not hurt him. Within couple of days, the mosquitoes stopped biting him at all and then all his life he never slept with mosquito net and he never got hurt by mosquitoes.

Sardar Raghbir Singh Bir wrote some excellent books which include the following titles:

Sarb Rog ka Aukhand Naam - This books talks about curing oneself through Naam and Gurbani.
Chardi Kala - This book contains chosen articles that bring Chardi Kala to one's life.
Safal Jeevan - This books talks about how to have a successful live - both worldly and spiritual.
Ramzi Kahaniyaan - This book contains some fictitious stories that are full of spirituality and spiritual secrets. A must read for serious seekers.
Ardaas Shakti - This book talks about the concept of Ardaas in Sikhi and how to do such an Ardaas that gets heard by Vaheguru jee.

Bir jee writes of his experience after stopping to dye and tie his beard. He writes how he started getting treated differently everywhere he went. If he would be standing in a queue, he would get moved to the top because of his appearance etc.

It is a good idea to read his books.

Koi Harya Boot Rahiyo Ri by Nanak Singh