My catechetics professor in college, Sr. M. Johanna, warned all of us future catechists to "beware of the millstone" ... leading little ones astray and such.
Yesterday I was trying to explain "creation from nothing" to my 2nd and 4th grade nieces. So, I had them make a paper airplane using brightly colored paper and then instructed them to make a paper airplane without using paper. Of course they couldn't. "This is how God creates. When we make things, we have to use things that already exist. But God creates out of nothing."
Their eyes were wide open in amazement. The lesson had struck home.
At the end of the day, I asked my 2nd grade niece what she had learned during the day.
"God likes to make paper airplanes from nothing!"