There is a saying in embryology, "ontogeny recapitulates phylogeny". What this means is, the stages of human embryo development are closely mimicked by the evolutionary development of animals from a single cell organism (fusion of egg and sperm), to invertebrates such as jelly fish, to higher invertebrates such as worms, to vertebrates such as amphibians, fish, mammals, and then man.
Likewise, there are stages in the development of the Buddhist Law which are reflected in the enlightenment of the practitioner who embrace the Law at a particular stage of its development. Thus, for example, the enlightenment of the Theravadin practitioner reflects the Theravadin Law. Since the pinnacle of development of the Buddhist Law is the Scripture of the Lotus Flower of the Wonderful Law, the enlightenment of the practitioner of the Lotus Sutra surpasses that of the practitioner at any other stage of development of the Buddhist Law. The most important matter is always the Law one embraces, not the priests, leaders, or body of believers.
The lifeblood and transmission of the Law is the Law itself [Sutra scrolls and Gohonzon]. Believing that the lifeblood is transmitted through priests, living [or dead] masters [mentors], or the body of believers, is to arrest one's development in a stage of Buddhist practice so far from Supreme Enlightenment (fully realized man) that it is barely recognizable from the deluded state. This is analogous to an embryo arrested in the early stages of embryologic development.