In "Golden Rules of Public Speaking", You will observe that there is nothing that can be substituted for personal sincerity. Unless you thoroughly believe in the message you wish to convey to others, you are not likely to impress them favourably.
Therein lies the key to successful oratory. When the truth of your message is deeply engraved on your own mind; when your own heart has been touched as by a living flame; when your own character and personality testify to the innate sincerity and nobility of your life, then your speech will be truly eloquent, and men will respond to your fervent appeal.
There is an erroneous impression that in order to make a successful speech a man must have unusual natural talent in addition to long and arduous study.
Consequently, many a person, when asked to make a speech, is immediately subjected to a feeling of fear or depression. Once committed to the undertaking, he spends anxious days and sleepless nights in mental agony, much as a criminal is said to do just prior to his execution. When at last he attempts his "maiden effort," he is almost wholly unfit for his task because of the needless waste of thought and energy expended in fear.
All successful speakers do not speak alike. Each man has found certain things to be effective in his particular case, but which would not necessarily be suited to a different type of speaker.