Many religious texts allude to all creation coming from The Breath (or Word) of God. Whether you are a believer or an atheist, you can agree on the science of energy. Energy is carried in both thoughts and sound; therefore, words are incredibly powerful in our plane of existence.
Words, like a nuclear reaction, create energy. Guard your words and thoughts like you would any incredible power source. They should be used only when and where necessary and needn’t be on display all the time.