How do you know that it wasn't just a story that someone made up?
Simple. Practice and results. The Dharma works for me. It worked for millennia of practicing Buddhists. Why would I doubt it? There's an issue with thinking you can pick out what parts of the teaching to reject. Then you're calling the Buddha himself and the entire enterprise into question.
I'm aware of how Baha'is feel about the Buddha's teachings, but I don't wish to offend you by harsh criticism of your approach. I actually admire the Baha'i religion.
There are reasons Baha'is are simply wrong to assume we don't have the Buddha's teaching. Much like scholars do with Jesus, the Buddha can be accurately placed into the India of his day. The Buddha was in most ways a man of his India.
His following appears exactly how we'd expect from what we know of the period. Several new thought movements arose in India. Jainism, Ajivika, Carvaka, and Ajnana. Together with Buddhism, these schools are all categorized as heterodox (nastika) schools of Hinduism.
The schools share several points of commonality like rejection of the Vedas, reimagining or abandoning the Atman, and a turn from the Brahmin rites to a stronger moral practice.
We possess histories of how thought schools arose in India. Contrary to one specific Baha'i view- Hindus and Buddhists did not just pull our teachings out of the air. We have history telling us how things were. We have Hindu and Buddhist, as well as Jain authors confirming things about one another's thinking because of debates.
If the historical nature of Buddhism as a thought system can be questioned, you may as well reject everything we know historically about the evolution of Indian thought.
Buddhism does not have to stand on it's own authority here. It corresponds to the attempted reforms taking place within Indian thought in the Buddha's time. It looks exactly how we'd expect a school of thought arising from that period to look.
Much like scholars can place Jesus in the Judea of his time and see how Christianity was shaped by it. Scholars can do the same with the Buddha and his India.
I admire Baha'is, but I simply don't agree with you here about Buddhists distorting the Lord's teaching, and frankly- I know enough eastern history to know better.
Take the two vehicles as another bit of evidence. The Mahayana and Theravada vehicles of Buddhism. They have two distinct lineages for their teachers, as well as transmitting literature and tradition into texts.
If Buddhists had really made up a bunch of stuff about what the Buddha taught- you should expect wide variations between two movements with differing lineages from the Buddha's disciples.
Instead, we see 97% agreement in Buddhist doctrine, with the only real differences being in emphasis on certain points of the teaching. Bear in mind we're talking distinct lineages. It's a shame the Hinayana schools didn't survive because that could make our case stronger and clearer.
This is exactly what we'd expect if two lineages transmitted the same teaching from the founder, but not if we gradually corrupted or twisted it over time as Baha'is think.
You'll also forgive me I hope, if I don't take the word of a 19th century Persian with probably no knowledge in Hinduism or Buddhism OR any reference to their practice as my authority for measuring Buddhism.
Peace