From the day that Abdu'l-Baha first set foot in the United States, he shared with others his message about the need for unity. He took that same message to Europe. Here is a quote from a talk that Abdu'l-Baha delivered in England:
My hope is that through the zeal and ardour of the pure of heart,
the darkness of hatred and difference will be entirely abolished,and the light of love and unity shall shine;this world shall become a new world;
things material shall become the mirror of the divine;human hearts shall meet and embrace each other;
the whole world become as a man's native country....
~ Abdu'l-Baha, Abdu'l-Baha in London, p. 38