I just finished Season 3.
The cloned humperdoos were odd and comical (I liked the tap dancing part) but did not make a great deal of sense in that it's hard to imagine that the church could keep control over the bloodline of Christ for over 2000 years. Nor is there any evidence that Christ had sex. But even if he had, his son would have had to have had sex with someone else and his son, likewise, and so on, so that there would be a significant watering down of the initial genetic information, right? Like your ancestor from 2000 years ago would not be expected to share huge similarities with you, would he/she?
As for the Church or its affiliates running a con game, well the minute the Roman imperium got involved with the church (Constantine's mother converted, as did many high placed women under the Empire, and he converted on his death bed), eventually adopting it as the state religion (a real departure from the multiple faiths that were practiced without interference so long as they paid taxes) the potential for corruption on all levels was there. The big father who explodes near the end of season 3 is an incarnation of sloth, gluttony, greed, anger, pride, envy, nearly all of the 7 deadly sins (lust appears to have been missing). I apologize for the long parenthetical inserts but I'm lazy today.
What is sort of comical is that everyone seems to be running a scam: vampires (Les enfants du sang), granma (Angelville), and the church/private corporation combo behind the Grail. You get a guy who has something genuinely supernatural and it is not isolated goodness, but a divine reflection of all those earthly bodies that are purportedly there as beneficial agencies but actually busy either stealing worldly goods or worse from the marks who subscribe to them. Where this all leaves our preacher remains to be seen.
I kind of don't get the whole "I borrowed my satan suit from the wardrobe of the Stephen King "The Stand" miniseries strain though. Satan makes deals to drag the living into hell because God is on the lam? and why is God in a dog suit, unless he's decided to reverse the spelling of his name and thinks it would be cute? And why is he focused on Tulip? The anus faced guy is just annoying. Hitler is funny, but where they are going with that is beyond me.