One has to speak his or her own message. It is very difficult to speak the message of another person. The testimony of faith, miracle, blessing, conversation, healing, power, and such are best told in the first person. To testify of the faith of someone else lacks the dynamic of personal authenticity.
We must speak the message of Christ Jesus with our own lips, and in our own way. Silence is the killer. Silence is implied consent to some other message. Not to say anything is worse than not knowing anything. Not to say something is to have said something.
“No one can write an authentic speech for another man. It is as impossible as writing his love letters for him or saying his prayers for him. When he speaks to the people, he and not someone else must speak. For it is much more important that he is genuine than that he is bright, clever, ingenious, entertaining, eloquent or even grammatical. Anyone who knows what he is doing can say what he is doing, and anyone who knows what he thinks can say what he thinks.” Walter Lippman (1889–1974), American writer, journalist.
“For whoever is ashamed of me and of my words in this adulterous and sinful generation, of him will the Son of Man also be ashamed when he comes in the glory of his Father with the holy angels.” Jesus