Love for Sikhism.

The principles of the Sikhism being clear, concise and easy to follow attract every human being. Persons of other religions also consider this religion to be supreme and dispenser of purposeful sermons to its followers. Many anecdotes are available in the Sikh history that show that many leaders of other religions adopted Sikhism and became famous followers of Guru's house.

Of the anecdote, one of the famous incident found mentioned relates to Saain Main Mir Ji, who was the jewel of the Qadri sect of the Muslims. He developed such an ardent affinity for Sikhism that he stayed with Guru Ji for ever.

source: Selected Episodes from Sikh History.