Is this even a question worth asking? Doesn’t everyone know what Christian apologetics is?
I would suggest that we need to define Christian apologetics clearly. It is bad definitions of apologetics that lead to some people and churches rejecting apologetics. Some people define apologetics as attempting to bully people into faith with a barrage of intellectual arguments. While they might not use those words, this ends up being the form of apologetics they reject.
What is apologetics?
Apologetics comes from the Greek apologia, from which we get the word apology. People are quick to clarify that we do not apologize for being Christians. However, from the original meaning of the word, that is exactly what we do.
When my son hits my daughter (not that that would ever happen!), we tell him to apologize. He then goes on to explain why he hit her. We then tell him that we were not looking for his reasons, we were looking for an expression of regret. But technically our son would be correct (not in hitting his sister).
Make sure to check out my Apologetics Resources.
An apology is about giving a reason or a defence for something. Apologetics is not limited to the Christian faith. If you can give a reason why you think hockey is the greatest sport, you have just done apologetics. Christian apologetics is simply doing the same thing but for the Christian faith.
I like James Sire’s definition of Christian apologetics:
Christian apologetics lays before the watching world such a winsome embodiment of Christian faith that for any and all who are willing to observe there will be an intellectually and emotionally credible witness to its fundamental truth.
I also like John Stackhouse’s definition:
I suggest that anything that helps people take Christianity more seriously than they did before, anything that helps defend and commend it, properly counts as apologetics, and should be part of any comprehensive program of apologetics.
What I like about these definitions is that they can include philosophical arguments but are not limited to them. As helpful a the cosmological argument might be, Christian experience and social justice can also be used as apologetics. We should not limit ourselves to a needlessly small number of defences for the truth of the faith.
So what is Christian apologetics?
Christian apologetics is the reason why we believe Christianity to be true. Thankfully, there are many reasons for us to present to those looking for the truth.
See also my post What Christian apologetics is and is not.