Would you like to be active as an apologist? Great! So what do you need to know to be an apologist?
The common sense answer would be that an apologist needs to know about apologetics. However, apologetics is more of an attitude than a body of knowledge. If you look at the topics being taught in any apologetics program, you will see that it is drawing from numerous other fields of study. What makes it apologetics is how you use it.
Here are some topics that apologists should seek to have a good handle of.
While logic is officially a part of philosophy, it is really something that is used in every field. You need to be able to formulate a good argument and be able to recognize errors in logic.
Much of the work of the apologist is defending orthodox Christian theology. How can you defend what you do not understand? You need more than a Sunday school understanding of the Trinity or the incarnation. Spend some time reading through a good systematic theology.
Nothing beats a good solid knowledge of the Bible. Before reading introductions, get into the primary source. Read the Bible, both Old and New Testaments, multiple times. Get to the point that you can recognize the Law from the Prophets, the synoptic Gospels from John. Paul from James.
4) New Testament Studies
This is different from the Bible in that it is a familiarization of the current trends in New Testament studies. What are scholars saying about the historical Jesus, textual criticism, Pauline theology, etc. This is the battleground for much of apologetics.
I am convinced that much of the trouble we see is because of bad historical methods. There is a reason why almost everything is blamed on Constantine. The Jesus myth theory is built on a solid foundation of bad history. Recognize bad history from good history.
I hesitate to include this one. Not because many Christians equate apologetics with philosophy but because philosophy is so big that it covers just about everything. However, it is good to at least understand the arguments for and against the existence of God. If you have the time and inclination, take on other philosophical issues as you are able.
This is not a comprehensive list of every subject related to apologetics. At the same time, it is good for a person serious about apologetics to have at least a basic understanding of each of these subjects. You may want to specialize in one area but it is still important to read in these other areas. A well-rounded apologist always has an important role.