In this paper, I will examine how the presence of evil makes it unreasonable to believe in the existence of God by using arguments and propositions presented in Mackie`s ``Evil and Omnipotence`` and Van Inwagen`s ``The problem of Evil, Air and Silence``. Mackie`s paper examines various fallacious solutions presented by the theists against his presented problem of evil and he also, explains the validity of his position as a friendly atheist. On the other hand, Van Inwagen paper explains that there