Since the Bible speaks to all of life, either directly or indirectly, there is no part of our lives which is not affected by theology. Like theology, apologetics also applies to every aspect of our living. The difference between the two is in terms of emphasis. Whereas theology focuses on the application of Scripture to our lives, apologetics focuses on defending what we believe and practice. There is also a difference between apologetics and evangelism.
Evangelism is concerned primarily with the proclamation of the gospel.
Apologetics supports and undergirds evangelism by justifying its claims. I have had conversations with atheists where it would have been impossible to intelligently press the claims of Christianity without at least a basic understanding of apologetics. As we examine the subject of apologetics, we find that two distinct forms of it are in use. One form is called presuppositional apologetics, and the other, evidential apologetics. The following is a brief description of these two positions.