[T]he lotus flower symbolizes the most important Bodhisattva practices in Mahayana Buddhism. In Chapter Fifteen, “Bodhisattvas from Underground,” it says:

The Buddha’s children have studied the way of Bodhisattvas well. They are no more defiled by worldliness just as a lotus flower is not defiled by water.

The lovely lotus flower grows out of muddy water and is not defiled by it. In the same way, Bodhisattvas, persons who put the Buddha’s teachings into practice, can live in the midst of a world defiled by vice and corruption, and yet not be contaminated by it. They can teach and awaken other people while keeping their own minds pure. They can save others, however, only when they live with them here in this evil world.