A line caught the young monk’s eyes: “All Buddhas arise in the human world; no one achieves Buddhahood in heaven.” With that verse, all doubts hanging in his mind evaporated…
The Buddha lived not in seclusion, but among people. Every day he walked barefoot to villages to beg for food. When he met a farmer, he used examples from farming to talk about the meaning of life.
No matter who he met—a butcher, a prostitute, a bandit, a slave, a scholar, or a child—he would talk to them, according to their temperament and intellectual faculty, to inspire them a little and alleviate their suffering.
How did a man named Siddhartha become an Enlightened One? By realizing the truth of life and cultivating himself in the human world, he understood the Principle of Karma.
All existence and phenomena arise because of the coincidence of causes and conditions (or Dependent Origination). As these causes and conditions change, all things correspondingly cease to exist. With such an understanding, Siddhartha attained enlightenment.