The argument from reason begins with the fact that we are capable of making valid logical inferences, and then it aims to show that this fact is incompatible with some underlying assumption of atheism. There are four such arguments that, taken together, push me toward theism. The first, already discussed in a previous post, is an argument against a specific type of atheism called eliminative materialism. That version of the argument justifies a realist view of selves, persons, conscious states, and thoughts.
The second argument from reason is not aimed at atheism per se. Rather, it is aimed at an idea that is embraced by many theists and atheists alike: determinism. Thus, this second argument from reason is an argument for free will. It is an important part of my rejection of atheism because most atheist philosophers affirm determinism on the grounds that free will (or at least, the non-determinist version of free will) is very hard to make sense of on an atheistic view of reality, and I happen to think that they are right. So if determinism is false, that poses a significant challenge to atheism.