Sooner or later, you will have to part from even your dearest friends. But one friend will never leave you, even though you may never be aware of its existence — Buddha-nature, pure awareness. You begin to discover it by listening to the teachings of a spiritual master. The ties will deepen as you cultivate sustained mental calm and profound insight into reality. In the end, you will discover that it has always been near you and will always be with you. This is the truest friendship you can ever cultivate.

-- Dilgo Khyentse Rinpoche