Tertullian

“ Now, in as far as nothing ought to be without a cause, that is, without a proof (because if it be without a cause, it is all one as if it be not, not having the very proof which is the cause of a thing) , in so far shall I more worthily believe that God does not exist, than that He exists without a cause. For he is without a cause who has not a cause by reason of not having a proof. God, however, ought not to be without a cause, that is to say, without a proof. ”

“ For although most persons believe in Him, they do not believe at once by unaided reason, [9] without having some token of Deity in works worthy of God. And so upon this ground of inactivity and lack of works he [10] is guilty both of impudence and malignity: of impudence, in aspiring after a belief which is not due to him, and for which he has provided no foundation ”