From the Writings of 'Abdu'l-Baha

Blessed souls whether Moses, Jesus, Zoroaster, Krishna, Buddha, Confucius, or Muhammad were the cause of the illumination of the world of humanity. How can we deny such irrefutable proof? How can we be blind to such light?... 

- ‘Abdu’l-Baha  (The Compilation of Compilations, vol. I, Extracts from the Baha’i Writings on Buddha, Krishna, Zoroaster and related subjects)