What was the main believe idea of Buddhism?

Sometimes when I'm asked to describe the Buddhist teachings, I say this:

(1) Everything is connected;

(2) Nothing lasts;

(3) You are not alone.

These first three are really just a restatement of the traditional Three

Marks of Existence: non-self, impermanence, and suffering. The fact

that we all suffer means we are all in the same boat, and that's what

allows us to feel compassion.

(4) Life is full of suffering

(5) Suffering exists because of our desires and aversions.

(6) There is a state of mind in which suffering ends (enlightenment).

(7) There is a path to attain this state; That path is called the Eight Fold Path.

Items 4 - 7 are the Four Noble Truths.

(8) Bodichitta (Loving- Kindness / Compassion) is the first step to

enlightenment (and to solving the world's problems)

(9) The 5 Precepts concisely describe a moral life

The 5 precepts are: (1) not to take the life of any sentient being, (2) not

to take anything not freely given, (3) to abstain from sexual

misconduct and sensual overindulgence, to (4) refrain from untrue

speech, and (5) to avoid intoxication, that is, losing mindfulness.

(10) Mindfulness of thoughts and actions are the key to wisdom and therefore

to the path of enlightenment.