Reason #1:  Because the Bible Tells You To:  

Plain and simple, we have a mandate as found in 1 Peter 3:15. 

“But sanctify the Lord God in your hearts: and [be] ready always to [give] an answer to every man that asketh you a reason of the hope that is in you with meekness and fear” (KJV)

We are commanded to be ready with an answer for those that ask.  For many Christians today, they are content just to answer that their belief is merely their personal religion, with no qualitative difference from any other belief system, no matter how different or illogical the other religions might be.  The Bible makes no such allowances.   Just as Elijah stood on Mount Carmel, clearly declaring that either the Lord was God, or Baal, and there was no room for dual affections, the apostles made it clear that God Almighty had punctuated our mundane world in the man Christ Jesus, and repentance and faith was the required response on man’s part.  As ambassadors for Him, we are to “make an appeal” on God’s behalf (2 Cor. 5:20) that people should be reconciled to God.   Moreover, that appeal ought to be as persuasive as possible. (2 Cor. 5:11).  

Although in many cases, this “apologia” was a recounting of one’s personal testimony or experience of meeting the Lord (Acts22:1-22) and more frequently, a recitation of prophecies and how they have been fulfilled in Jesus (Acts 2:14-36; 3:17-26; 7:1cf;  particularly with Jewish audiences), this defense of the Gospel also includes presenting a trans-cultural God that extends outside the traditional parameters of “religion”.  In Paul’s presentation on Mars Hill (Acts 17:19-31) he cites pagan poets and philosophers to make the case that his God is Lord over all, regardless of nation, culture, or religion.  The Gospel is the metanarrative of humanity, or overarching story of the human race.  

We can extrapolate from this the principle that the apostles did not shy away from extending the reach of their message into any and every pertinent realm of learning.   Paul certainly had to study those pagan poets in order to be able recite them, and demonstrate how the pagan Greek philosophy really had it’s nexus in his Gospel.   One could even speculate farther than that.  When Paul was in Ephesus, after he met resistance in the synagogues, he then brought his lectures to the “School of Tyrannus” (Acts 19:9) and taught there for two years.  We aren’t treated to the exact content at the School of Tyrannus in Ephesus, but it is interesting to note how different the flavor of Paul’s epistle to the Ephesians is from his other writings (save the epistle to the Colossians, another Hellenistic church).   It is impossible to ignore the allusions to Plato’s Idealism, and the metaphysical implications of our being “In Christ”, “seated in heavenly realms”.    There can be very little doubt that Paul was able to clearly demonstrate how the Gospel encompassed whatever was truthful in the classic philosophers, just as Philo did with Judaism at about the same time.   With respect to contemporary apologetics, this establishes the pattern for us that a healthy understanding of the Divine does not have to be relegated merely to a study of scripture.   Other disciplines have an integral although subordinate role. 

Reason #2: Because Truth Is Objective, And It Matters:

The prevailing mindset of our multicultural society says that Truth, and most particularly religious truth, is a subjective issue, and ought not be subject to scrutiny, nor impressed upon others.  One’s religious beliefs are seen as safely tucked away in an untouchable compartment, safe from critique, and more importantly, far removed from any impact on our public lives.   That is a nice, comfortable sentiment for the secularist, however, it doesn’t take into consideration the fact that almost all religions make some type of truth claims, and in many cases, those truth claims intersect and sometimes collide with the demands and standards of the rest of our community.   Take one tragic example:  a couple are devout Christian Scientists who believe, as their church teaches, that sickness is “unreal” and therefore do not patronize doctors or hospitals.  Their young son experiences a chronic but treatable intestinal blockage.  Because their religious belief prohibits them from bringing him to the hospital, he dies a slow and agonizing death from the blockage.  In this case, their adherence to a belief resulted in their child’s death.   Should this particular belief be exempt from critique?   Of course not.   It cost the life of an innocent child.   Most other examples do not have such a dramatic and tragic ending, however, it is undeniable that one’s sincerely held beliefs do not operate in a vacuum in relation to the other facets of our lives.   Our beliefs affect the outcome of our lives in the here and now, and, if the Bible is true, our beliefs affect the outcome of the life hereafter.

 If we could make a broad generalization, it is safe to say that wrong belief ultimately is bad for it’s adherents.  Right belief, that is, belief, which coincides with reality and God’s revealed truth, is good for it’s adherents.   As Christians, we understand that the “Truth shall set you free” (John 8:32) and conversely understand that error entangles and enslaves.    Therefore we are not content with a live and let live philosophy with regard to religious beliefs.   Not all religious beliefs are beneficial, or even benign.  Some are downright malignant, based wholly in error and deserve to be exposed and refuted.  Not every religious belief can be “true”.  Some are mutually exclusive with other beliefs.   We are enjoined to “contend the faith, that was once and for all delivered to the saints (Jude 3).  Of course, that doesn’t mean becoming argumentative, or triumphalistic in one’s conversation.   Apologetics properly applied helps provide a calm assurance so that one interject the truth with gentleness and respect, and thus help another individual form a more orthodox worldview.

Reason #3:  Because Christianity Is, At its Core, Indivisibly Connected To Apologetics:

It is difficult to miss the fact that the New Testament is largely comprised of motifs meant to persuade the reader of certain truths.  The constant formula of “this happened that the words of the prophet XXX might be fulfilled” reverberates throughout the Gospels.  When Paul is presenting to the Corinthians the matters of “first importance”, he punctuates the abbreviated description of Jesus’ advent with the words “according to scripture” (1 Cor 15:3,4).  These books were written for the purpose of presenting evidence and persuading individuals to a certain point of view.

Likewise, the early church beyond the age of the apostles was engaged in the same work of apologetics and persuasion.  Justin Martyr’s (d. 155 AD) best known writings are his First and Second Apologies.  Most of Irenaeus’ writings are a refutation of heresy (Against Heresies),  as is much of Tertullians’ and Origen’s.  By volume, the amount of apologetic works still extant from the first two centuries dwarfs the amount of all other works combined.  The mission of the church from its earliest days has always been to present evidence for faith in Christ, and to be unrelenting in its quest to establish objective truth.   There have been a few unfortunate departures from that, most obviously the attempts during the dark ages to coerce conversion by the edge of the sword, or by threat of torture, as well as a few blundering missteps against the progress of science, but the ideal of advancing God’s Kingdom by the spread of true knowledge has remained the same. 

Conclusion:

Apologetics is an indispensable segment of the teaching-shepherding ministry of the church.  Particularly in this age, which has been inundated by Subjectivist and Postmodernist thought, the need for quality scholarship from Christian authors in all disciplines has never been greater.  The church right now stands ankle-deep in the mire of epistemological uncertainty, contemplating whether wading out deeper might make her more “relevant” to the rest of the world, which is already up to it’s chin in the muck.   Christians collectively need to firmly place their feet on the Rock.   There are solid reasons to believe, and the Church does not need to fear what it might find if it intrudes into other disciplines.   This is not to say that all Christians need to become super-scholars or that apologetics somehow is the “silver bullet” in evangelism.  Ultimately, it is God that draws men to himself, and His Spirit that convicts, and when it comes right down to it, people are more likely to be won over to Christ by seeing authentic and caring lives than they are some water-tight argument.  Just the same, our obligation to make a rational, accurate and coherent defense of the faith still resides with us.   It is such a presentation or defense that God, as our “co-laborer” may use to extend his Kingdom.