Here's my personal summery of the Bible.
The Christian Bible is a collection of mythological tales, often mistaken as historical facts, that initially attempt to explain first cause, along with morality lessons that were common in ancient Mideastern society. It also includes some uplifting poetry. The myths include claims made by an individual who claims to be the Saviour of mankind, along with some humanistic myths that are meant to encourage positive behavior toward other humans. The central character of the NT may have been based on a real or fictional person. The book often contradicts itself, and makes irrational claims, which is likely explained by the fact that it had many different authors that wrote these stories over a long period of time. It appears as if tribal identity is an important aspect as well. The book finally ends with a section referred to as Revelations. That part of the Bible appears to be the rantings and ravings of someone suffering from severe psychosis. There are many different versions and translations of the book, and some parts were not considered accurate enough by those who decided how to compile these stories.
Is that brief enough?
If not, how about this. The Christian Bible is a book of theological mythology which is often taken as literal truth, despite the fact that there is little historical evidence for most of the claims made. Many of the claims sound fictitious and are not based on anything rational. This is explained by the fact that it was written during a time prior to the scientific method, reflecting the limited knowledge available during the times it was written.
Still to long? How about this.
The Christian Bible is an ancient book based on fantasy that was believed to be real during the time it was written. It describes prophets, gods, miracles and other fantastical ideas that were probably common during ancient Mideastern times.
And here's an afterthought, not to be considered a summary.
Despite the fact that the book does contain some examples of what the modern world might associate with humanism, the Christian sect commonly referred to as evangelical, has gained dominance in the contemporary US. Sadly, most of those in this group have put more emphasis on the more tribal, judgmental parts of their Savior's writings, while often ignoring the more positive, tolerant aspects. But, this seems to be changing as more US citizens are becoming less religious and fewer are identifying with Christianity, while some Christians prefer to hold a very liberal, symbolic view of the Christian Bible, putting their emphasis on the more positive aspects of Christian theology. There are even some Christian atheists that embrace the more inspiring traits of the Biblical Savior while not assuming that any of the claims made are to be taken literally. I see this as a positive development.
Don't like it? Well, at least I tried to give a shot.