A human being could be anyone human. The nature of that human being could be loving or could be brutal. There are brutal human beings in the world.
So i guess the message writer here wants to convey is that 'if you are a human being, then be like one' (Dont be brutal, cruel etc towards others)
Your example
A human being will not mean till he is educated and intelligent.
This sentence might be modified in the following way -
The meaning of 'a human being' in the true sense of the word will not justify unless he is educated and intelligent.
Another example
- Should we really call the terrorists as human beings ? (They are not worthy to be called as human beings)
On the other hand
Being human is Awakening the humility, compassion, kindness, love and care within you towards mankind. It is willing to extend a hand to help the needy in the society.
For your reference -
There is a big NGO which is named 'Being Human' run by the veteran Indian actor Salman Khan.