This thought is not mine. It has been around on emails and internet sites in various formats. Nevertheless I thought it worthwhile to post here. I don’t know the original source or even if the story is true (if anyone knows, please let me know).

One day, a professor of a university decided to defy his pupils. He asked, “Did God create everything that exists?”
A student answered bravely, “Yes, He did.”
“Everything?” asked the teacher.
“Yes, everything.”
“In this case, God also created evil, correct? Because evil exists.” said the teacher.
To that, the student had no answer and remained in silence. The teacher was delighted at the opportunity to prove one more time that faith was only a myth. Suddenly, another student raised his hand and asked, “May I ask you a question, professor?”
“Of course.”
“Does cold exist?”
“Of course”, answered the professor. “Did you never feel cold?”
“Actually, sir, cold does not exist. According to studies in Physics, cold is the total and complete absence of heat. An object can only be studied if it has and transmits energy and it is the heat of an object that transmits its energy. Without heat, the objects are inert, incapable to react. But cold does not exist. We created the term cold to explain the lack of heat.”
“And darkness?” continues the student.
“It exists”, replied the professor.
“Again, you’re wrong sir, darkness is the total absence of light. You can study light and brightness, but not darkness. The prism of Nichols shows the variety of different colours in which the light can be decomposed according to the longitude of the waves. Darkness is the term we created to explain the total absence of light.”
And finally, the student asked, “And evil, sir, does evil exist? God did not create evil. Evil is the absence of God in people’s hearts, it is the absence of love, humanity and faith. Love and faith are like heat and light. They exist. Their absence leads to evil.”

Now it was the professor’s turn to remain silent.

The name of the student was, Albert Einstein.