The spread of the Cause is similar to the growth of early Christianity – ‘Abdu’l-Baha explains

In the afternoon ‘Abdu’l-Baha met some of the friends who had called at the San Francisco house, but it was not until evening that He met the entire assembly at the Baha'i headquarters in the Lick Building. After expressing His happiness at finding Himself in such a well-organized assembly in the distant West, He compared the spread of the Cause to the growth of early Christianity and spoke of the small number of Baha'is at the time of the exile from Persia. There were thirty stages on the way from Tihran to Baghdad, He said, and in those thirty stages they did not find one Baha'i, and yet now in each one of them there are great numbers of Baha'i friends. Despite the fact that the governments of Persia and Turkey united in tyranny and oppression to extinguish the lamp of God, yet its radiance extended throughout the world, even as far as San Francisco, half way around the world from Its birthplace. He exhorted the believers, few though they might be, to strive day and night to give forth the summons of God, inviting the souls to the Kingdom; otherwise God would create those who would hoist the standard and conquer the cities of the hearts. These meetings were for the Baha'is and were quite informal.

- Ella Cooper  (Unpublished manuscript, October 4, 1912)