April 9

The differences among the religions of the world are due to the varying types of minds. So long as the powers of the mind are various, it is certain that men’s judgements and opinions will differ one from another. If, however, one single, universal perceptive power be introduced—a power encompassing all the rest—those differing opinions will merge, and a spiritual harmony and oneness will become apparent. For example, when the Christ was made manifest, the minds of the various contemporary peoples, their views, their emotional attitudes, whether they were Romans, Greeks, Syrians, Israelites, or others, were at variance with one another. But once His universal power was brought to bear, it gradually succeeded, after the lapse of three hundred years, in gathering together all those divergent minds under the protection, and within the governance, of one central Point, all sharing the same spiritual emotions in their hearts. 
(‘Abdu’l-Baha, ‘Selections from the Writings of ‘Abdu’l-Baha’)