What tenets must a person accept to be a Buddhist?

In Buddhism your should follow the 3 fold training:

• Live a life of morality
• Develop control over your mind
• Develop wisdom towards the working and natural of your mind with a view to eradicate all sources of stress

In addition you should seek inspiration from the Triple Gem and develop confidance / refuge in the Triple Gem with a view towards developing the qualities in the Triple Gem to complete your 3 fold training and come out of stress. Lack of confidence / refuge in the technique and practice would entail you to not practice properly hence not getting out of stress.

To come out of you should identify stress, the reason behind the stress, that you should overcome stress and the way out of stress which is the 3 fold training.

No argument with any of the answers.

Here is what might be called "barebones Buddhism" 1) follow the breath with awareness 2) have compassion and understanding for all beings including oneself 3) dedicate one's efforts and life for the benefit of all.

There are ways to express that in Buddhist terms, but if you wanted to explain it to a child and hit the major points, that is enough.

I have no formal education in Buddhism, and have never been part of a Buddhist community, so take what I say with a grain of salt, but given I didn't feel a deep sense that any of the existing answers were saying what I'd want to share on this topic, here I am, for whatever it's worth.... (Andrei Volkov came close though!)

What follows is a perspective on the core of the Four Noble Truths.... I see Buddhism as a path - motivated by and cherishing empathy and compassion - to improving quality of life. This is completely achievable given the insight that quality of life is a direct function of:

1. lacking attachment/lust/longing/avarice/neediness

2. lacking aversion/hatred/fear/disgust/contempt

3. being fully involved in the moment - to:

   • appreciate whatever enjoyment, empathetic engagement, experience and/or learning is on offer,

   • perceive and accept reality, and

   • plan and act to guide the future towards increased likelihood of a better quality of life for others and ourselves

     • this despite understanding and accepting (per 1.) that those plans/efforts may not actually pan out; we just need sincerity of intent combined with best effort to make educated decisions, though there's often very subtle and complex ways in which we affect future quality of life

Everything else - recommended codes of conduct, exercises of breathing and mind - they're tools to help use the moment to better realise and act consequent to an understanding of the three factors above.

In the Zen tradition in which I've practiced, I was taught "Refrain from evil, do good and purify this mind." Everything else was guidance about practices (particularly seated meditation) that could help accomplish those goals. There was not any particular emphasis on 'being' a Buddhist. It doesn't really matter what I think, imagine or believe; things are what they are. So, while I would say that there are plenty of useful lists of tenets, ultimately you don't need to believe anything to be a Buddhist or, more to the point, to be a Buddha. It's about the practice.

What tenets must a person accept to be a Buddhist?

Here's what the Buddha had to say about it:

In what way, Bhante, is one a lay follower?”

“When, Mahānāma, one has gone for refuge to the Buddha, the Dhamma, and the Saṅgha, in that way one is a lay follower.”

“In what way, Bhante, is a lay follower virtuous?”

“When, Mahānāma, a lay follower abstains from the destruction of life, from taking what is not given, from sexual misconduct, from false speech, and from liquor, wine, and intoxicants, the basis for heedlessness, in that way a lay follower is virtuous.”
_{-AN 8.25 & SN 55.37 (They are both worth reading in their entirety)}

And what does it mean to take refuge? It means trusting that the Buddha [as the name implies] awakened, that what he taught is realizable & verifiable for oneself and that his community of followers are worthy of generosity & respect:

'We will be endowed with verified confidence in the Buddha: "Indeed, the Blessed One [the Buddha] is worthy & rightly self-awakened, consummate in knowledge & conduct, well-gone, an expert with regard to the cosmos, unexcelled as a trainer for those people fit to be tamed, the Teacher of divine & human beings, awakened, blessed."

'We will be endowed with verified confidence in the Dhamma: "The Dhamma is well-expounded by the Blessed One, to be seen here & now, timeless, inviting verification, pertinent, to be realized by the wise for themselves."

'We will be possessed of verified confidence in the Sangha: "The Sangha of the Blessed One's disciples who have practiced well... who have practiced straight-forwardly... who have practiced methodically... who have practiced masterfully — in other words, the four types [of noble disciples] when taken as pairs, the eight when taken as individual types — they are the Sangha of the Blessed One's disciples: worthy of gifts, worthy of hospitality, worthy of offerings, worthy of respect, the incomparable field of merit for the world."
_{-SN 41.10, Seeing the Sick}

Main tenets? Here how I see them:

• There is good (health, peace, nirvana) and bad (sickness, trouble, suffering, samsara) -- versus "nothing matters" i.e. nihilism.
• By acting a certain way we can change our life, and the lives of people, away from the bad and towards the good. -- versus "everything is predetermined" i.e. fatalism or "it's all because of society, I cannot do anything" -- i.e. victim consciousness.
• Enlightenment is real and achievable in one life -- versus "Enlightenment is a fiction" or "It takes 10000 lives to attain".

I'm not even perfectly sure about your Christian tenets; for example,

• So far as I know, it's only opinion (it's not canonical) that those are the minimal tenets
• There's even perhaps a dispute about one of your tenets: a dispute between mainstream Christian churches (Catholic and Protestant) about whether "accepting Jesus" is the way to life (the Catholic church teaches that faith is not sufficient)

There are several (many) Schools of Buddhism.

Here is one article, titled Two Main Schools of Buddhism, which claims that,

The areas of agreement between the two schools are as follows:

• Both accept Sakyamuni Buddha as the Teacher.
• The Four Noble Truths are exactly the same in both schools.
• The Eightfold Path is exactly the same in both schools.
• The Pattica-Samuppada or teaching on Dependent Origination is the same in both schools.
• Both reject the idea of a supreme being who created and governed this world.
• Both accept Anicca, Dukkha, Anatta and Sila, Samadhi, Panna without any difference.

All of these are words which you can easily look up; for example, Four Noble Truths, Anicca, etc.

IMHO the central, first, or 'minimal' part of the Christian Bible is the Gospels, which describe the life and words of Jesus.

Similarly, IMHO the central part of the Buddhist scriptures are the parts which describe the life and words of the Buddha.

The most central part of the Buddha's doctrine is perhaps what/everything he taught in his first sermon after he became enlightened, which is called "The Setting in Motion of the Wheel of Dharma", a.k.a. "The Sermon at Benares".

You might have noticed that Buddhists like numbered lists: four noble truths, eightfold path, etc. Another is the "triple jewel", i.e. "the Buddha (himself), the Dharma (his teaching), and the Sangha (his 'church')".

The "four noble truths" are, approximately:

1. Suffering exists (gives various example including poverty, disease, old age, death)
2. Suffering is caused by desire/attachment/craving (to have what you don't have, or to keep what you can't keep)
3. There's a way which leads to the end of suffering
4. That way is the eightfold path, which is: Right views; right aspirations; right speech; right behavior; right livelihood; right effort; right thoughts; and right contemplation.

Note that what I listed above is tenets of doctrine (i.e. words or beliefs); but (at least one school of) Buddhism is or requires more than only doctrine or faith: it requires or consists of "right effort", "right behaviour", etc. (as listed above and as described/defined/analysed in considerable detail).

You just need to take refuge in the Triple Gem sincerely.

1. Buddham saranam gacchami - I go to the Buddha for refuge.
2. Dhammam saranam gacchami - I go to the Dhamma for refuge.
3. Sangham saranam gacchami.- I go to the Sangha for refuge.

Refuge here means spiritual refuge. It doesn't mean you reject medicine for physical ailments like in some Christian sects.

Taking refuge will be broken for ordinary people when they die, but this breaking is blameless and does not bring bad results. On the other hand, breaking the taking of the Triple Refuge during one's life is very serious. This is broken whenever a person goes for refuge to a teacher outside the Buddha's Dispensation or when a person is disrespectful to the Triple Gem. Those who are Noble Ones will never break with their refuge. But ordinary people, through ignorance, doubt, and wrong knowledge about the special qualities of the Buddha, the Dhamma, and the Sangha, are susceptible to breaking their refuge.

Read more at How to Take the Triple Refuge.