Christian apologetics is simply a defense of the faith. We are commanded to "always be prepared to make a defense to anyone who asks for a reason for the hope that is in you"(Pet. 3:15).
At the outset, the notion of defending Christian theism is contrary and offensive to all secular opinion, such opinion that would have the rest of the world believe that proof cannot be given for God's existence and correspondingly, what God requires of humanity.
As for what constitutes Christian apologetics let me say this: Christian apologetics is that voice of reason that defends the faith against a world that is spinning out of control with bad philosophy and theology having an agenda to discredit our faith as being in opposition to reason and scientifically unverifiable.
A Christian apologetic answers the skeptics with mouth stopping force.
Who is qualified to do this?
Christian apologetics does not exclude anyone that is a Christian. Indeed all Christians are commanded and charged with this responsibility (1Pet. 3:15) Here is a word of encouragement for those who do not feel competent to do this.
The abilities of the common man are made uncommon in the most simplistic of God's ways. The sword of the Lord (his word) is sharper than any crafty weapon invented by man. It is true that one can become a professional at apologetics, having gone through many years of formal training. But this is not necessary to defending the faith and few make apologetics their "profession" as compared to the many that are of the more laity type. One does not have to have a string of diplomas to defend the faith. The only requirement is to know God, and to be skilled in his word.
It always amazes me how God makes foolish the wisdom of the world. All secular arguments are dashed to pieces on the hard rock of God's word when the weather gets stormy on the sea of debate. It does not take a genius, a doctor of theology or philosophy, a master of divinity, college degree, or any formal training whatsoever to turn the heavy artillery of God's word on the enemies of Christ. They don't stand a chance. The simplest of us can give a defence of what is alive in our hearts, at work in our lives, and is present in the ordering of the affairs of the world. This truth is open for all to see and know.
The simple principle of truth that the Christian apologist rests on is summarized in Psalm 36 and is the subtitle for World View Ministries. "With you is the fountain of life; In your light we see light" (Psalm 36:9). God has given us "light" which serves as the source of all revealed knowledge about him, ourselves, and the world we live in. (Psalm 36:9)
All secular opinion that tries to give an account to the origin and meaning of our existence amounts to nothing but groping around in the dark. The highest esteemed philosophers and scientist of the world, past and present, are doing nothing but fumbling around in the dark trying to describe faint images and impressions of what are really aspects of the divine by using fantastic imagination and even blasphemous license with unethical ethical systems.
It is precisely at this very point that the Christian apologist is most advantaged. The Christian worldview not only gives an answer for ethics, an account for the origin universe, and the laws of nature, but the Christian can also account for why it is that the atheist even bothers himself with such issues of life.
The impulse that gives these great thinkers the presumption and audacity to inform us in the ways of what exists and what does not, what is right and what is wrong, what is law and what is not in the universe, even what is beautiful and what is not, rests on the spark of light that yet remains in them, and by God's goodness graces them. God is the source of their feelings of oughtness, duty, love, beauty, justice, etc. Though dim and imperfect, this light is but the mere flickering of a flame. All of humanity is created in God's image. Herein is light. God's common grace respecting natural revelation also gives light. Such light is all borrowed capital from God and is imperfect (on man's part, not God's) in that they fall short in their accounting of things, and in that they would rather remain in darkness rather than turn to God and be exposed in their deeds.
The Christian world view even accounts for theories of "ethics" that are completely skeptical in denying the very concept of right and wrong. Such a love of darkness is fully explained in a Christian world view.
The Christian that understands this does not need to be fearful of defending the faith against even the "brightest" of our day.