Question: I’ve heard that Guanyin Bodhisattva is an ancient Buddha (‘Brightness of Right Dharma’ Buddha). Why must a Buddha return as a Bodhisattva to guide us? Is it such that a Buddha cannot guide us until he transforms into a Bodhisattva?
Answer: Buddhas are not obliged to remanifest as Bodhisattvas. They simply do so naturally and with great ease since they have perfect endless compassion for all beings. They do not backslide from their attainment of liberation and wisdom.
Buddhas can guide us perfectly to enlightenment as they are perfected Bodhisattvas. We can see this from the example of Shakyamuni Buddha himself. When Buddhas manifest as Bodhisattvas, they further exemplify how to walk the path to Buddhahood. Hope you can sign up for the next round of this course to learn more: https://thedailyenlightenment.com/2012/04/course-the-universal-door-of-guanyin-bodhisattva-from-seeking-to-becoming-compassion
Question: If Guanyin Bodhisattva is an ancient Buddha who is perfectly enlightened, how did she become the chief Bodhisattva disciple of Amitabha Buddha? Was she not fully awakened after all?
Answer: This is skilful manifestation to set a good example for all to see, and to guide more beings to enlightenment. Buddhas can manifest as anyone deemed suitable out of great compassion. They are not attached to any status. They can have multiple manifestations too, since they have complete supernormal powers. In this sense, ‘Brightness of Right Dharma’ Buddha does not express compassion only as Guanyin Bodhisattva. This is further explored in the course recommended in the link above.