Credible: offering reasonable grounds for being believed.
Credulous: ready to believe, especially on slight or uncertain evidence.
Many Christians are credulous. Fairly often I receive a long e-mail that has been forwarded to me of something wonderful that God supposedly has done. At the end of this wonderful letter I am instructed to forward to ten or thirty or everyone on my mailing list within ten days. If I do I will receive a great blessing, normally in lots of dollars. If I do not follow the instruction then something bad will happen to me. God could well have done this wonderful thing, but when I see the instruction at the end I know the whole thing is a lie or euphemistically, a fabrication. Satan is the master liar. A good liar does not go around saying “I am a liar, do not believe me.” He says that he is telling the truth. The false prophet does not say, “I am a wolf in sheep’s clothing I am here to eat sheep.” He says, “I am a sheep.”
Both the truth teller and the liar say that they are telling the truth.
Discernment! Look for verifiable facts in the story, names, addresses, dates, witnesses, hospitals by name, and doctors by name. If they are listed, call them. If they are not there, do not forward the message, at least not to me.
If you have the gift of discernment; use if for the benefit of the whole body.