The people of Kalama asked the Buddha who to believe out of all the ascetics, sages, venerables, and holy ones who, like himself, passed through their town. They complained that they were confused by the many contradictions they discovered in what they heard. The Kalama Sutta is the Buddha’s reply.
- Do not believe anything on mere hearsay.
- Do not believe in traditions merely because they are old and have been handed down for many generations and in many places.
- Do not believe anything on account of rumors or because people talk a a great deal about it.
- Do not believe anything because you are shown the written testimony of some ancient sage.
- Do not believe in what you have fancied, thinking that, because it is extraordinary, it must have been inspired by a god or other wonderful being.
- Do not believe anything merely because presumption is in its favor, or because the custom of many years inclines you to take it as true.
- Do not believe anything merely on the authority of your teachers and priests.
- But, whatever, after thorough investigation and reflection, you find to agree with reason and experience, as conducive to the good and benefit of one and all and of the world at large, accept only that as true, and shape your life in accordance with it.
The same text, said the Buddha, must be applied to his own teachings.
- Do not accept any doctrine from reverence, but first try it as gold is tried by fire
According to the Wikipedia entry for the sutta, it is contained in the Aṅguttara Nikaya (3.65) of the Tipiṭaka. (https://en.wikipedia.org/wiki/Kesamutti_Sutta, accessed 10 January 2021).
You can listen to sermons by Buddhist monks/priest and read all the Buddhist books out there, yet if you have no True Belief: That you have an unborn-undying pure immortal soul, that you suffer because your Mind is caught between your Pure soul and the stained impermanent phenomenal world, and that you can liberate your soul and end suffering forever. This is the original teaching of Sidhartha Gautuma in his teaching of Bhramayana,
Without knowing that you have a soul, and the cause of your own suffering, then all the sermons from Buddhist monks and all the books you read are useless and meaningless.
This is why The Buddha said, “Come see, come know for yourself” – because he knew that once a sentient being fully understood the nature of their suffering, that they would understand his teachings.
Lastly, for those who don’t believe in a Soul, or say that “In Buddhism, there is no soul”, this is a mistake and they then mistake this Sutta as to say that, ‘nobody knows nothing!, and that is solipsism!