Original: Baba said that in other ages this role was fulfilled by Zoroaster, Rama, Krishna, Gautama Buddha, Jesus, and lastly by Muhammad. Meher Baba describes the Avatar as "a gauge against which man can measure what he is and what he may become.
Simplified: Meher Baba said that in the past the Avatar had been on Earth as Zoroaster, Rama, Krishna, Buddha, Jesus, and Muhammad.