Whereas early Buddhism taught that just one Buddha came into the world in each era, Mahayana Buddhism taught that there were multiple Buddhas and bodhisattvas existing in the cosmos at the present time.
They can help the Mahayana devotee reach nirvana or a heaven-like place (such as a Buddhist Pure Land) on the way to nirvana.
Therefore, faith in these Buddhist divinities was an important aspect of Buddhist salvation. In Mahayana, one does not even need to become a monk in order to attain nirvana.