Apologetics is effective
The argument that apologetics is effective claims that arguments for and against an idea are effective at persuading people to change their position. Strictly speaking, apologetics refers to both arguments for and against a concept. Both theists and atheists are divided on the issue of its effectiveness.
Many people spend a great deal of energy on apologetics of religion. This includes the new atheism movement and many prosthelytizing groups such as Ray Comfort, William Lane Craig and Christian Apologetics & Research Ministry.
"Our primary task in our discourse with one another should be to identify those beliefs that seem least likely to survive another thousand years of human inquiry, or most likely to prevent it, and subject them to sustained criticism. [...] This spirit of mutual inquiry is the very antithesis of religious faith."
Fundamentalists are often not persuaded by arguments but people with less extreme views may benefit from hearing a different perspective:
"In my experience, waverers and Sunday-only observers can find forthright challenges to religious pretensions a relief and a liberation. They give them the reason, sometimes the courage, to abandon those shreds of early-acquired religious habit that cling around their ankles and trip them up."
Apologists argue that apologetics is justified even if only a minority of an audience responds to it:
"Frankly, I think that those who regard apologetics as futile in evangelism just don’t do very much evangelism. [...] When you reflect that only a minority of people who hear the Gospel will accept it and that only a minority of those who accept it do so for intellectual reasons, we shouldn’t be surprised that the number of people with whom apologetics is effective is relatively small."
Some theists claim apologists are useful in strengthening beliefs they already hold, which is a questionable motivation since strengthening belief for its own sake is not sensible and is susceptible to confirmation bias.
"If the arguments of natural theology and Christian evidences are successful, then Christian belief is warranted by such arguments and evidences for the person who grasps them, even if that person would still be warranted in their absence. Such a person is doubly warranted in his Christian belief, in the sense that he enjoys two sources of warrant."
Christian apologists also use Biblical arguments to support the validity of apologetics.
Apologetics is useful for influencing culture since it can influence debates and exchange of ideas. 
Some people decide their effort is better spent elsewhere:
"Moreover though I am a strong advocate for free thought on all subjects, yet it appears to me (whether rightly or wrongly) that direct arguments against christianity & theism produce hardly any effect on the public; & freedom of thought is best promoted by the gradual illumination of men's minds, which follows from the advance of science. It has, therefore, been always my object to avoid writing on religion, & I have confined myself to science."
Apologetics arguably undermine the work of those who try to promote understanding between opposing factions. Argumentation may be perceived as confrontational and be off-putting to people who might otherwise be friendly. When used in debates, apologetics tends to polarize opinion and alienates one's opponent.  Humans find admitting error to be psychologically difficult, so an adversarial debate is not likely to directly influence the speakers. On the other hand, debates may sway audience members in either direction.
- "The aggression is counterproductive and damages the reputations of atheists writ large, just as Muslim extremists or extremists of any religious faith damage the reputations of their co-faithful. "
Ineffective for evangelizing
Some argue that logical arguments are generally unconvincing and other means of instilling belief are available, such as humor. Many religions use childhood indoctrination, which largely bypasses logical argumentation, to recruit believers.
"One chooses logical argument only when one has no other means. One knows that one arouses mistrust with it, that it is not very persuasive. Nothing is easier to nullify than a logical argument: the tedium of long speeches proves this. It is a kind of self-defense for those who no longer have other weapons."
Detrimental to apologist
Debating may lead people to bad behaviour, such as rudeness or arrogance, which they internally rationalize as necessary to win an argument. Apologetics may therefore become a distraction from ethical behaviour. 
Some claim that apologetics is idolatrous.
- "Yet if our apologetics is driven not by our love for God, in whom we place our faith, but by our fear of labels, then our apologetics is just idolatry, making our defense of Christianity an idol to man. "
Overly dependent on human rationalism
Rationality is unreliable? 
Faith is better? Faith is pleasing to God? 
Not used in scripture
Religion does not need defending
Useless with irrational people
"Those who believe without reason cannot be convinced by reason."
Paul the Apostle emphasised he was preaching using demonstrations rather than argumentation:
"And my speech and my preaching was not with enticing words of man's wisdom, but in demonstration of the Spirit and of power:"
In that case, it would be good for apologists to produce "demonstration of the Spirit and of power". Since they don't, modern Christianity does not fulfill biblical signs. Chrisitan apologists argue that Paul is hardly consistent on this point (as if they helps their case). 
- ↑ 
- ↑ 2.0 2.1 2.2 2.3 
- ↑ [http://www.xenos.org/essays/approach-christian-apologetics
- ↑ Darwin, C. R. to Aveling, E. B., 13 Oct 1880
- ↑ 5.0 5.1 T E Hanna, 3 Reasons Why I Gave Up Christian Apologetics
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- ↑ 9.0 9.1 9.2 
- ↑ 10.0 10.1 10.2 Norman L. Geisler, An Apologetic for Apologetics, 1996
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