What is the Purpose of a Long Life?

To make your life better and to make better the lives of everyone you know or associate with the rest of your life.

When you move towards having a long life it tends to be because you are kind to yourself and others. Your kindness towards yourself keeps you alive a long time and your kindness towards others also extends their lives as they are grateful for your kindness.

When you become a generator of kindness by the way you govern your thoughts and actions it makes life worthwhile for others too as well as yourself.

So, the actual purpose of your life and civilization in general is fulfilled by your kindness towards yourself and others.

It usually starts with yourself. When you see that you can choose not to be a victim of yourself or others, you start to become a generator of kindness towards yourself and others.

It doesn't mean you don't defend yourself or others, it just means you become incredibly more efficient and practical about everything you do based upon human kindness towards yourself and others.

So therefore, Right mindful compassion and kindness  becomes the key to life itself and a long life if possible for as many beings as possible during your lifetime.

Also, your demonstration of kindness and compassion becomes an example to all others to follow your lead.

And this is how the saints of All religions (and even more commonly saints who are walking around without any particular religion) that you know of come to be.

There is a saying, "Be kind to all beings because they might be Angels you are unaware of".