William Lane Craig, in his book Reasonable Faith, makes a distinction in the types of apologetics that I’ve found helpful.
First, there is the positive, or offensive, apologetic. Positive apologetics is concerned with proving Christianity. This is broken down into two categories, natural theology and Christian evidences. Natural theology is mostly concerned with supporting theism, that is proving the existence of God. Some examples are uses of the ontological, teleological, cosmological and moral arguments. Christian evidences is concerned with showing how Christian theism is true. Some examples of Christian evidences are the fulfillment of prophecy, the claims of Christ, and the historicity of the gospels.
Secondly, there is the negative, or defensive, apologetic. Negative apologetics is concerned with defending Christianity against its objectors. This, likewise, has two categories: defense against objections to theism, and defense against objections to Christian theism. Some examples of the objections to theism that need defense are the problem of evil and incoherence to the idea of God. Some examples of objections to Christian theism that need a defense are objections posed by contemporary science, modern biblical criticism and the biblical record.
Craig says that the positive apologetic is the most important, because if you prove Christianity to be true using its methods, you do not need the negative apologetic at all. If you have successfully proven your point, you in turn will not need to defend against objections.
I believe this to be true in many cases. But I believe that when someone’s worldview is firm, it can be difficult to argue the positive apologetic first. You may have to break down that person’s worldview first, before you can rebuild it with the truth of the Christian worldview. For example, you may have to deal with the objection of biblical criticism before you can talk about the historicity of the gospels. You may have to deal with the problem of evil before you can talk about the existence of God. You may have to deal with the questions of science before you can argue the cosmological argument for the beginning of the universe. Each of these are connected, but in each instance you may sometimes need to begin with the defensive apologetic before you can go to the offensive to prove your point.