The Buddha said the true nature of all beings is that of enlightenment.
We know all the scriptures were written by monks, perhaps 500 or more years after Gautama Buddha passed away. Most of the time they just wrote down what they wanted, or from their own ideas and opinions.
"Buddha nature" is one of the first lies that Buddhist monks tell people. People donate to the monks who practice meditation because they want to invest in someone who is spending all his time on a path they think will get to Enlightenment. But it is not virtue to donate to the monks.
Someone only can have Enlightenment and Buddha nature by removing every falsehood from inside themselves. But if he did that he'd be a Tathagata in this lifetime, and it is ultimately very rare to encounter a living enlightened being.
One of the first things you said in this thread is a reference to what Buddha said.
Actually, your reference itself was false. You said that Buddha said enlightenment cannot come through meditation, yet, Buddha stated enlightenment can come through adherence to the Four Noble Truths and the Eightfold Path, one of the limbs of that being right concentration/samadhi/meditation.
"Most of the time they just wrote down what they wanted, or from their own ideas and opinions."
I would ask you for a citation, but it obviously would not be helpful. You only write down from your own ideas and opinions and think it is Truth.
Again, you are cherry picking.
"Most of the time they just wrote down what they wanted, or from their own ideas and opinions."
When your master's webpage at:
http://www.members.tripod.com/tathagata2000/questions_and_an...
Says:
"What is the proof about a Tathagata? > The proof is in the Buddhist scripture."
Seems contradictory, no?
Gautama Buddha taught for about 40 years and met lots of people. If we try to summarize just a few parts, of _all_ of his teachings over his entire teaching career, what do we come up with?
The two things are as follows:
1. Transmigration
2. The law of cause and effect
An Enlightened being tells about 'what is' in the world, and can teach people how the world works. That's exactly what Gautama Buddha taught, although he taught it quite a long time ago.
Finally, there's more evidence in the content of the prajna paramita sutra, if you have seen that one, which explains about some cases in perfecting oneself and opening one's wisdom eye. No one can explain that content without already having been Enlightened.