Mahayana Buddhism has changed in many ways, but an enduring core is the ideal of the bodhisattva, and the bodhisattva spirit is what inspires Mahayana work for social well-being. Following the model of Ananda Guruge in his book Humanistic Buddhism for Social Well-being, I shall review several scriptural sources along with a case study. By the sixth century in China, the guidelines for bodhisattva practices were outlined in three bodhisattva precept texts – the Universal Bodhisattva Precepts in the Da fangdeng tuoloni jing, the Lay Precepts in the Youposai jie jing, and the Brahma-net Precepts in the Fan-wang jing – but also were expressed in popular social movements such as the Three Levels Sect (sanjiejiao) led by the Buddhist master Master Xinxing (540-597) based on an apocryphal text, the Xiangfa jueyi jing. After reviewing the major Mahayana sources concerned about social well-being in sixth century China, I conclude by proposing that bodhisattva practice in our contemporary world needs new guidelines for community development, such as the principles outlined in the Sarvodaya Shramadana movement and the Earth Charter.