Baha’u’llah has come “for the education and training of all humanity”

… Baha’u’llah has manifested for the education and training of all humanity. He is the Teacher of all, whether rich or poor, black or white, oriental or occidental, northern or southern. (‘Abdu’l-Baha, from a Tablet to Mr. and Mrs. Ostburg, Boston, Mass; Star of the West, vol. 2, no. 5, June 5, 1911)