Were Writers Of The Bible Mediumistic?

In this episode, Dr. Betters answers the question, "What I don't understand is that the Bible says it is wrong to visit fortune tellers or spirit mediums, but the people who wrote the bible often relied on what they were told by 'angels'. How do we know that these 'angels' were good angels, and in order to of been able to communicate with them, the writers of the Bible must of in some way been mediumistic? Is there a contradiction here? I hope I’m explaining myself in a way that you understand."