"Did you know the leading cause of lung cancer is not actually a cigarette? It's your DNA. You could smoke for years and nothing would ever happen to you. This whole war against smoking is just to restrict the farming of tobacco."

It sounds like a preposterous statement, doesn't it?

Not to hear Mohammed Qahtani say it.

"I used these arguments," he said, "…even though I just made them up." As the laughter of audience members at the Toastmasters 2015 World Championship of Public Speaking died down, Qahtani drove his point home:

"A simple choice of word can make the difference between someone accepting or denying your message," Qahtani said. "You can have a very beautiful thing to say, but say it in the wrong words and it's gone."

"Words have power. Words are power. Words could be your power," he told the rapt audience.

Are you exercising your power?

Are you choosing the right words?

The words you use, whether verbally or in writing, can influence how others perceive you. They factor into the decisions people will make about you. They can build — or destroy — your relationships.

In an age where words seemingly spill out of us onto social networks, in presentations, in casual conversation, on blog comments and in the content we increasingly create and share with the world, are we giving our words enough forethought?

See Qahtani's moving and inspirational speech in full — it will make you reconsider the power of the words you use each day: