The Collaborative International Dictionary of English v.0.48:

Atheize \A"the*ize\, v. t.
   To render atheistic or godless. [R.]
   [1913 Webster]

         They endeavored to atheize one another.  --Berkeley.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Atheize \A"the*ize\, v. i.
   To discourse, argue, or act as an atheist. [R.] --
   A"the*i`zer, n. --Cudworth.
   [1913 Webster]