Gautama Buddha had various teachers in using different paths to seek his spiritual goal, but in each case he found those other ways defective. He wished to find a way to end the suffering of all beings, so after trying those other paths, he sat under the Bodhi Tree with the firm intention to not get up until he had found what he was looking for. And he succeeded.
There are different degrees of enlightenment, and there are different ways of describing the stages, so it is hard to compare, but the Buddha’s enlightenment is recognized by his followers as being the most profound—certainly more profound than that of Eckhart Tolle, based upon Tolle’s description of his. This is not a denigration of Tolle. It’s just a recognition that there are differences in attainments.
Enlightenment is a potential of all beings, and there are many paths to reach it. In Buddhism there are many Buddhas spoken of, who came before Gautama Buddha, and some that will come after him. As well, there are enlightened Bodhisattvas and Mahasattvas. In other spiritual traditions, there are many enlightened beings spoken of as well.
The Buddha had to make his own way forward and he taught his followers so that they could find their way to enlightenment too. It’s easier to succeed if you have a teacher, but it’s not necessary. This is an important point. The Buddha found his way—finally—without a teacher.
However, without a qualified teacher there are many pitfalls and even danger that one might succumb to, without the wisdom of a guide. The Buddha succeeded, but would we have known of him if he hadn’t? There are presumably many other enlightened beings throughout history that did not teach, and who had no teacher to recognize their attainments. What if the Buddha had never shared his accomplishment with others—would he still have been known? Perhaps he would have been seen as just a crank mumbling about gibberish, and quickly forgotten.
See: “A Life of Buddha” by Asvaghosha Bodhisattva, Sacred Books of the East, Edited by Max Müller, Vol. XIX, 1968
And: Manjushri’s Summation, Chapter Two, Surangama Sutra, on Medium.com: https://medium.com/tranquillitys-secret/surangama-sutra-ce0017f10d2b?source=friends_link&sk=72d18baf4c053717a13c8463297c6240
Also see my article on The Danger Inherent in Modern Secular Meditation
Modern secular meditation focuses on techniques taken from ancient spiritual traditions, while jettisoning their deep wisdom born of long experience working with practicing meditators over centuries.
Friends link: https://medium.com/tranquillitys-secret/the-danger-inherent-in-modern-secular-meditation-2a2fe0617ffd?source=friends_link&sk=3feb7a775cd31c2e60c8afff38031f64