The Cause of Bahá'u'lláh is the same as the Cause of Christ

The Cause of Bahá'u'lláh is the same as the Cause of Christ. It is the same Temple and the same Foundation. Both of these are spiritual springtimes and seasons of the soul-refreshing awakening and the cause of the renovation of the life of mankind. The spring of this year is the same as the spring of last year. The origins and ends are the same. The sun of today is the sun of yesterday. In the coming of Christ, the divine teachings were given in accordance with the infancy of the human race. The teachings of Bahá'u'lláh have the same basic principles, but are according to the stage of the maturity of the world and the requirements of this illumined age. ('Abdu'l-Baha, Baha'i World Faith, p. 400)