(A) As a Great Teacher:
1. Preacher of Truth : Guru Nanak Dey Ji was a great teacher of humanity. Guru Sahib attained enlightenment in the thirtieth year of his life. Guru Sahib travelled widely to spread his message. Guru Sahib spread the gospel of Truth in every nook and corner of the Punjab. Everywhere, people were impressed by his personality and message. Guru Nanak Dey Ji taught to abandon the materialistic dsires, selfishness, and greediness and enjoined upon his followers to lead a pious life. Guru Sahib taught those principles which he himself practised in his personas life.
2. A Guru for the Whole Humanity : The teachings of Guru Sahib were not meant for any particular community, place, or nation, rather they are for the whole world. Prof. K.S. Narang opines that his message was not just for one period of time. It is eternal. Guru Sahib’s teachings were so rational and complete that even modern rationalists cannot find any shortcomings in them. The main aim of his teachings was the welfare of the whole humanity. It was only with the spirit of the welfare of the whole humanity, that Guru Sahib undertook hard journey to Burma, China, Tibet, Arabia, etc.
(B) As the Founder of Sikh Religion : Guru Nanak Dey Ji founded the Sikh religion.
There are some fundamental principles of Sikh religion which are found only in Sikhism but not in Hinduism or Islam. For example, Guru Nanak Dey Ji started the institutions of Sangat and Pangat which were the important features of the new faith. Secondly, Guru Nanak Dey Ji did not appoint his son as successor to Guru-gaddi but gave it to his devotee Bhai Lehna. By this act, the Guru tradition became very significant and the Sikh religion was founded. The Sikh religion continued to develop during the period of next nine Gurus and the Sikh religion established itself as a full-fledged religion.