The professor of a university once challenged his students with this question.
'Did God create everything that exists?'
A student answered bravely, 'Yes, He did'.
The professor then asked, 'If God created everything, then He created evil.
Since evil exists (as noticed by our own actions), so God is evil. The 
student could not respond to that statement causing the professor to
conclude that he had 'proved' that the belief in God was a fairy tale, and therefore worthless.
Another student raised his hand and asked the professor, 'May I pose a question?'
'Of course', answered the professor.
The young student stood up and asked, 'Professor does cold exist?'
The professor answered, 'What kind of question is that? Of course cold
exists... haven't you ever been cold?'
The young student answered, 'In fact sir, cold does not exist. According to
the laws of physics, what we consider cold, is in fact the absence of heat.
Anything is able to be studied as long as it transmits energy (heat).
Absolute Zero is the total absence of heat, but cold does not exist. What we
have done is to create a term to describe how we feel if we don't have body heat or we are not hot.'
'And, does darkness exist?', he continued. The professor answered, 'Of course'.
This time the student responded, 'Again you're wrong, sir. Darkness does not
exist either. Darkness is in fact simply the absence of light. Light can be
studied, darkness can not. Darkness cannot be broken down. A simple ray of
light tears the darkness and illuminates the surface where the light beam
finishes. Dark is a term that we humans have created to describe what
happens when there's lack of light.'
Finally, the student asked the professor, 'Sir, does evil exist?'
The professor replied, 'Of course it exists, as I mentioned at the
beginning, we see violations, crimes and violence anywhere in the world, and
those things are evil.'
The student responded, 'Sir, evil does not exist. Just as in the previous
cases, evil is a term which man has created to describe the result of the
absence of God's presence in the hearts of man.'
After this, the professor bowed down his head, and did not answer back.
The young man's name was *ALBERT EINSTEIN*