The Vedic scriptures state that spiritual life begins when one inquires into the nature of the absolute truth, the Supreme Godhead. Gaudiya Vaisnavas are monotheists and know the personality of Godhead as Krishna, the All-attractive. But it is also recognized that the Supreme has unlimited names such as Rama, Buddha, Vishnu, Jehovah, Allah, etc. The ultimate goal of Gaudiya Vaisnavism is to develop a loving relationship with the Supreme Godhead.

The Vedas also tell us that the understanding of the self, as being non-material or spiritual by nature, is the preliminary stage of realization of the absolute truth. To understand knowledge of self-realization one must approach a genuine spiritual master, just as one learns the essence of any subject from a perfected practitioner.

The congregational chanting of the Maha mantra,

Hare Krishna Hare Krishna Krishna Krishna Hare Hare
Hare Rama Hare Rama Rama Rama Hare Hare

as promoted by Sri Caitanya, is accepted by the Vedas as the most effective means of self-purification in this age. The Vedas describe the mantra as a prayer to the Lord, "Please Lord, engage me in Your service".

Devotees may accept formal initiation into the chanting of the Holy Name vowing to abstain from intoxication, gambling, illicit sexual connections and the eating of meat, fish and eggs. ISKCON members believe indulgence in the aforementioned activities disrupts physical, mental and spiritual well-being, and increases anxiety and conflict in society. At the time of initiation devotees also agree to chant a prescribed number of mantras each day. You can read a brief history of ISKCON - here.