One of the most powerful arguments against the Christian God, which perhaps occured most powerfully in the works of Benedict Spinoza is a kind of pantheistic atheism. Augustine eleven centuries before Spinoza was alive to the implications of that type of pantheism and addresses it in the City of God.
If all this is so, however, who does not see what impious and irreligious consequences follow. Whenever anyone tramples on something, he tramples on a part of God. Whenever any animal is killed, a part of God is slaughtered. And I decline to speak of all those things which may occur to anyone who gives the matter some thought but which cannot be named wihtout shame. (IV 12)
Notice that Augustine's argument has one main strand. It is one to which he returns again and again and is the basis for his rejection of paganism. Augustine was very interested in maintaining the honour of God. To believe that God might be trampled on or slaughtered (an ironic comment from a Christian perhaps) was to submit God to indignity. Just like the pagans with their theatres, the pantheists submitted God to the indignity of being the sacraficed animal and the squashed ant. Indignity is a large part of Augustine's arguments about God: God in his view is not be associated with the work of the devil and part of Satan's purpose on earth is to confuse Godhead and sin. Its worth remembering always that this is a work of theology rather than philosophy or history.