The Buddha himself said: "I shall not pass into the final Nirvana, O Evil One,
until there be not only brethren and sisters of an Order,
but also lay-disciples of both sexes,
who shall have become true hearers, wise, well-trained, ready and learned,
versed in the scriptures, fulfilling all the greater and lesser duties,
correct in life, walking according to the precepts -
until they, having thus themselves learned the doctrine,
shall be able to give information to others concerning it, preach it, make it known, establish it, open it, minutely explain it, and make it clear-until they, when others start vain doctrines, shall be able to vanquish and refute them, and so to spread the wonderworking truth abroad. I shall not die until the pure religion of truth shall have become successful, prosperous, widespread, and popular in all its full extent-until, in a word, it shall have been well proclaimed among men!" [Mahaparinibanna Sutta]
There you have it, straight from the Exalted One!
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