Sikhi, or Indic faiths, is a way of life, i.e., 'Dharm.' There is no formal conversion process, but to be a Sikh, you must follow these rules: 1.) Believe in One God based on the Mool Mantra. 2.) Follow the teachings of the Ten Gurus. 3.) Consider Guru Granth Sahib as the eternal spiritual Guru. 4.) Believe in Khalsa and not follow any other human, group, dharm, or religion for spirituality. To become a Khalsa, you have to go through an initiation. The rules are very strict for a Khalsa. Read 'Sikh Rehat Maryada' for more information. People often ask, 'Why should I be a Sikh?' more as an argument rather than a genuine question. Such individuals are often looking to buy the best product or religion in the market. Sikhi is beyond such petty arguments.It is not about selling you gold but making you one; the Guru is the Philosopher's Stone. You can read Japji, Salok Mahala 9, etc., for a summary of Sikh philosophy.