Actually that is unprovable that man naturally has the passion to worship. A person can deny it and show it in his actions that he doesnt believe in a God, however, You cannont see what is in his heart.
'atheism of today is but a species of paganism', That is laughable because Christianity has more roots in paganism than athiesm!
Christmas,
Easter,
drinking the 'blood' of Christ
worshiping Idols such as the cross of statues of Mary and or saints etc.
A god having a child with a mortal.
I could go on...
If these arent pagen you should read up on your history!