In one of my seminary classes (Personal Evangelism), we were shown this incredibly powerful video. Without saying too much about the video, it is an incredible testimony to the mighty and glorious Savior that we serve. He has the ability to do amazing things and it only requires that we surrender to Him. It's hard work, but as you will see in the video, it is infinitely worth it.
Now, after you have dried your eyes, take a moment and think about what your cardboard testimony would say.