While in medical training, surgeons are encouraged to weigh the importance of each word spoken during an operation. As the anesthetic is given, fear may strike a patient if she hears someone say, "I'm going to shoot her now." Even a phrase such as "hook up the monitor" may be interpreted by a drugged patient as sounding like 'shake up the monster.' Can you imagine the impact on a half-dazed patient if she hears a doctor say, "This isn't my day!"
The same directions given by two different physicians could encourage or discourage a patient, simply by their tone of voice. One doctor's voice might suggest a prescription will work, while another's voice might convey reservations. Either would drastically affect the morale of a patient.
Theodore Roosevelt popularized an expression about the need for clear, precise communication. He called words with several possible meanings "weasel words"--by using them a speaker might weasel out of any commitment, claiming a different interpretation of the word.
The Bible also tells us again and again to remember the importance of our words. We are always to speak words of encouragement, hope, and faith to those around us.