From Notes from Lectures and Discourses of Volume 5 of The Complete Works of Swami Vivekananda
Speaking of the world-wide unity, before the Oak Beach Christian Unity, Swami Vivekananda said:
All religions are, at the bottom, alike. This is so, although the Christian Church, like the Pharisee in the parable, thanks God that it alone is right and thinks that all other religions are wrong and in need of Christian light. Christianity must become tolerant before the world will be willing to unite with the Christian Church in a common charity. God has not left Himself without a witness in any heart, and men, especially men who follow Jesus Christ, should be willing to admit this. In fact, Jesus Christ was willing to admit every good man to the family of God. It is not the man who believes a certain something, but the man who does the will of the Father in heaven, who is right. On this basis—being right and doing right—the whole world can unite.