Are cherubim and seraphim imaginary or are they real? The…

Are cherubim and seraphim imaginary or are they real? The reason I ask this is because I was listening to William Lane Craig talk about it and he was saying how they were not to be taken literal.

Here is the recent interview with William Lane Craig last week and if you start the video at 27:45 minutes in he starts talking about it.

Let me know what you guys think.