The belief that all major religions have the same spiritual source and come from the same God is a basic tenet of which faith?

The Bahá'ís is one of the youngest religions among the major ones, dating back from 1863, founded by Mirza Husayn Ali, proclaimed Bahá'u'lláh (God of Glory in Arabic) in Iran.

According to their beliefs, there is just one God, and several different religions have sprung due to different attempts to make a description of this God. However, these descriptions have come out to be distinct from one another because of contrasting experiences and interpretations of cultural backgrounds, giving birth to a variety of religions.