Even many SGI members believe in the teachings of the Three Stages School

"San-chieh (540–594) Also known as Hsin-hsing. A priest of the Sui dynasty who founded the Three Stages school (Chin San-chieh-chiao). He asserted that, during the third stage in the propagation of Buddhism, or the Latter Day of the Law (that he held had begun in 550), people should not adhere to any particular sutra but revere all teachings without discrimination. This school spread widely, but was proscribed in 600 by imperial decree because its doctrine contradicted those of the earlier schools and ran counter to government policy. It was again suppressed in 725 by imperial decree during the T’ang dynasty. This dealt the school a fatal bow, resulting in its rapid decline." -- SGI Glossary

Unfortunately, this school lives in the hearts of many modern Buddhists, including SGI [Interfaith] Buddhists.