Summary
Apologetics is the task of giving a reasoned defense of Christian theism in light of objections raised against it and of offering positive evidence on its behalf. There are several reasons why apologetics should be learned, with these reasons mainly geared towards the strengthening of ones' own faith and for providing the intellectual permission for open-minded seekers to come to believe in the truth claims of Christianity.Apologists use the rules of logic and evidences from nature and the physical world as tools to argue their case.
Apologetics, as with almost everything else in life, cannot provide a proof with 100% guarantee. Just as we cannot have a "watertight proof" that Caesar crossed the Rubicon, similarly, the apologist does not claim they can prove with certainty that God exists. Apologists make a more modest claim - they offer a series of good reasons and arguments that are more likely true than not. Layering probability on top of probability, a total case is built in which (it is hoped) reasonable people would find it unreasonable (and sometimes irrational) to believe alternative arguments.
