The Mahatmas are not yet Buddhas. A Buddha is a Mahatma of…

““The Mahatmas are not yet Buddhas. A Buddha is a Mahatma of the highest grade. A Mahatma is one who has become self-consciously alive in the spiritual part of his constitution, whereas a Buddha is one who has become self-consciously living in the divine-spiritual part of his constitution. The Masters are human beings, although lofty ones, and it is this that makes them so near and dear to us. They occupy the step immediately superior to ordinary humanity. They are soul-men in human bodies, feeling as men feel, understanding human woes and human sorrows, capable of cognizing what human failings and human sin are, and therefore having human hearts moved with tender compassion and pity. They know also the need, when occasion arises, of the strong and directing hand. They are brothers, tender-hearted men, great-hearted men, of magnificent spiritual and intellectual powers and faculties. 'Diamond-heart' is the term used when speaking of the Mahatma; and it has its symbolic meaning, signifying the crystal-clear consciousness reflecting the misery of the world, receiving and reflecting the call for help, reflecting the Buddhic splendor in the heart of every struggling soul on earth; but yet as hard as the diamond for all calls of the personality, the self-personality, and first of all of the Mahatma’s own personal nature. Should the Mahatma abandon his physical body and live in his other principles, he becomes de facto a Nirmanakaya, living in the auric atmosphere of the earth and working for mankind invisibly, thus becoming one of the living stones in the Guardian Wall.””

— G. de Purucker