Preparation: Get two identical 12 oz. cans of soda (i.e. Pepsi, Diet Pepsi, Mountain Dew, etc.), open one of the cans and empty it of its contents. Leave the other can just like it is, full and closed. Place the cans in a visible place in your speaking area so all your students can see them.
Opening: Gather your students together and have a student come up and stand beside you. Have the student carefully examine the cans and then have him/her tell the crowd what difference they can find between the two (they should say, one is open and empty and the other is not…or something to that effect).
After their examination and announcement, instruct the student to try to squeeze and crush the full, closed can using only their hands. (No feet, no crushing it on their head… they’ll just get hurt and it will explode. It’s very hard, but not impossible. So don’t bring Conan up to the front for this one!).
After several seconds of trying unsuccessfully, take the can and replace it with the open, empty one, and ask them to crush that can (they should be able to successfully achieve this task).
Now talk to the students about how sometimes in life the only difference between people is what is on the inside. People who don’t know the love of Jesus and His forgiveness and grace are like the empty can, as soon as the pressure of the world begins to weigh on them, they are crushed with relative ease. People who follow Christ are like the can that was full--though the pressures of the world still come and sometimes they are even greater, but when you are following Christ you can withstand these pressures and stresses much more than those who do not know Him.
Original Idea by Chris Wallis