Guru Nanak was born in 1439 at Talwandi. He said God is the ultimate truth which he described as "Sat Sri Akal". He worshipped God as Nirakar that means without any physical form. He condemned caste distinction and idol worship. His teachings have been compiled in Guru Granth Sahib. He advised people to follow the three principles of life: Nam Japo, Kirt Karo, Vand Chakho.