What is the origin of the idiom "one's head on a plate" and when to use it?

The idiom "one's head on a plate" has its origins in the Bible, specifically in the New Testament. It refers to the story of John the Baptist's execution, as recounted in the Gospel of Matthew and the Gospel of Mark. This expression is frequently used in political, legal, or professional settings, where individuals may face severe repercussions for their actions, such as being fired, facing legal charges, or enduring public humiliation.