Before answering the question, “why defend it?”, I need to unpack the words classical and monotheistic to clarify what is being defended and what is not being defended. Then I will talk a little about the method used to defend classical Christianity
When I use the term “classical” to refer to Christianity I am referring to the knowledge and beliefs that the early Christians held about Christianity . In other words, classical Christianity is what the founders of Christianity held to be true about God and later ratified into a book of scriptures, based on their original knowledge of God . The original Christians did not believe Christianity was corrupted. Or needed further revelations, evolutions, or conformity to modern day culture via revisions. Classical Christianity is an unchangeable understanding of God and reality. Mormonism, Jehovah’s Witness, Atheism, Deism, Islamism, Buddhism, Judaism, and Hinduism do not hold to a classical view of Christianity. At this point I am not arguing that this makes them mistaken. However, I am asserting that none of these competing religions logically hold to the classical monotheistic understanding of Christianity. This is obviously the case with something like Atheism, but no less the case for Mormonism, Jehovah’s Witness, Judaism, and Islamism.
I’ve placed the word monotheistic in between the words classical and Christianity to clearly express that what is being defended is the idea of a single (i.e. mono) God that is spaceless, timeless, immaterial, powerful, intelligent, personal and creator of all things created (i.e. the greatest possible, non-created, being).
Why defend classical monotheistic Christianity? The answer. Because it is defendable. It is not wishful/blind knowledge or an emotional safety blanket. Classical Christianity is not hinged on subjective claims, hope in the unknowable, relative experience driven praying, or irrationality. These things are not objectively or rationally defensible.
The fact is that classical Christianity hinges on a single historical event. If Christ did not rise, then Christianity is worthless. Period! This makes classical monotheistic Christianity the only religion of its kind to be testable and ripe for intellectual evaluation and investigation. Additionally, it is a practical, robust, and intellectually fulfilling philosophical explanation of reality unmatched at the table of ideas/worldviews.
I just asserted without proof what I am here to argue to be objectively true. For this I must given an answer. This site and its contents will be my answer.
Lastly, the main style or method used to defend Christianity on this site will be "classical apologetics". This style of defense is similar to "evidential apologetics". Both classical and evidential apologetics use evidences  in providing a cumulative defense for the rationality of the classical Christian view of reality.
For additional details about classical monotheistic Christianity and its essential doctrines read, "Essential Classical Christian Doctrines".
- In this video Greg Koukl explains the term "classical Christianity"
- I am refereeing to the Bible here.
- Referring to both direct evidence (e.g. Eyewitness testimony) and indirect evidence (e.g. circumstantial evidence from archaeology textual criticism, rational arguments).
- Slick, Matt. Classical Apologetics. https://carm.org. 11/23/08. https://carm.org/classical-apologetics
- Slick, Matt. Evidential Apologetics. https://carm.org. https://carm.org/evidential-apologetics
- Wallace, J. Warner. Yes, the Christian Worldview Is Supported by the Evidence. http://coldcasechristianity.com/. 02/23/15. http://coldcasechristianity.com/2015/yes-the-christian-worldview-is-supported-by-the-evidence/