Broadly speaking, there are three apologetic strategies. Picking an appropriate one for every occasion will aid an apologist’s success.
The first apologetic strategy involves defending one’s own position against objections.
For example, the problem of evil amounts to an objection to the Christian belief in God’s omnipotence and omnibenevolence. If one can successfully solve the problem of evil, then one has succeeded in rebutting the objection.
Reasons to use the defensive strategy: Rebutting objections is a modest aim. It is far more achievable than either a full-blown defense of one’s view or showing that the alternative view is false.
Weaknesses for the defensive strategy: The strategy does not show that one’s view is correct. One has only shown that it can be held without succumbing to objections.
The offensive strategy involves showing that the opponent’s view is false.
For example, one might want to show that moral relativism is self-refuting.
Reasons to use the offensive strategy: Okay, I have to admit that this kind of argument is deeply satisfying. It is also quite devastating to discover that one’s view cannot be true. Such a discovery leads one to ask what alternative might work. The apologist should be at the ready to offer his/her suggestions!
Weakness for the offensive strategy: Again, this does not directly show that one’s own position is the right one. However, if the options are limited to only two views and one of them is shown to be false, then the other one wins by default.
If one adopts a positive strategy, one mounts a case for a view by presenting evidence that directly (or indirectly) supports it.
A positive strategy might involve offering evidence for the resurrection of Christ.
Reasons to use the positive strategy: If one can successfully mount a case for one’s view, one has achieved quite a feat.
Weaknesses of the positive strategy: Mounting a full-blown case for one’s view is almost certainly the most difficult strategy to adopt. It requires a great deal of preparation. It will also involve replying to objections.
In sum, an apologist should not feel that only one strategy ought to be used. Apologetic strategies can be chosen for pragmatic reasons.
Sometimes it is not entirely clear which way one should go. For example, when confronted with a religious pluralist who holds that all religions are equally right, there is not one right strategy. One might try to respond to the objections the pluralist has to exclusivism or one might try to show that pluralism is false.
Picking the right strategy for the right occasion is part of what makes a good apologist.
For more, see John Feinberg’s Can You Believe It’s True?