Vivekananda explains the gist of Hinduism by quoting a sloka from "Baghavad Gita". In fact that also explains the concept of Universal acceptance of all religion.
From an audio release, about the Life and Works of Swami Vivekananda. Though it is not the actual voice of Vivekananda, we can feel the power of his thoughts on Hinduism, and his respect for other religions. (less info)