In ancient China, there was a peddler who sold weapons. He always said impressive things to attract customers. One day, he set up a stall at the market to sell his spears and shields.
First, he picked up a spear and shouted, "Come and see! This is my family's invincible spear. It can pierce through any shield, and nothing can stop it!" Everyone was curious and gathered around.
Then, the peddler picked up a shield and confidently said, "And this shield is also invincible! Nothing can pierce through it, and any attack is useless against it!" People were even more amazed and thought the shield was extraordinary.
At this moment, a child scratched his head and curiously asked, "You said your spear can pierce through anything, and your shield can block any attack. So what happens if you use your spear to pierce your shield?"
The peddler was speechless and didn't know how to answer. It turned out that his words contradicted each other. From this story, we can learn that our words and actions should be consistent and not contradictory, or else people will find us untrustworthy.