The well-known phrase, The utterance coming from the heart, will be accepted heartily indicates a precise and subtle mental reality, which could be used in the ways of influencing on the others as a vital principle.

As we know tongue and speech is the interpreter of mind and idea and also the scale of speaker's own belief determines evaluation of speeches.

It is not surprising that degree of belief of a hearer to an utterance has a close relation with the degree of belief of the speaker. One may say something apparently very excellent and good, but when his tone shows that he does not believe in it so much, it causes the hearer to doubt in the correctness of that issue. In contrary, if a subject is not very acceptable, but there are the evidences of his decisive belief in it, this provokes the curiosity and precision towards it, and makes them optimistic to that speech.

This too is noteworthy that not believing in a matter could not be totally hidden with mannered utterances, especially in speech that against most deeds, is full of delicacies through which spirit of emotions and mind of speaker will be manifested willingly or not.

Observing one's own speech is one of the important factors for its influence because it is possible that the utterance does not indicate the belief, but one's action is mostly the sign of belief.