What to do with the well-delivered miss?

By now I've listened to many a sermon. Hundreds. Nudging thousands. 

Some have been good, having excellent, relevant points, lifted from the passage.

Most have been adequate. Not overly memorable, but a solid explanation of the passage.

Other sermons haven't been good.
They have rambled and not been applied effectively.

I'm sure I've been guilty of serving up a few of the later. Maybe more than a few.

But there's one sermon which is harder to define.

Usually, these types of sermons are given at a conference when one of the primary speakers applies "their spiel" on the main stage.

What do you do with the sermon, which contains a well delivered point, but isn't connected to the bible passage?

Since the points are commonly derived from a book they've written or a presentation they've delivered many times, the points are made exceptionally well. But they totally ignore or misapply the scriptures.

I think we have little choice but, whilst accepting the point made, place the sermon in the "not good" category.

The reason?

When I hear a sermon, I'm expecting to hear from God based on the scriptures and anything else, whilst flashy, is a fail.