[user104658]

Originally Posted by LeatherTrumpet

well you have to give it the gloss to get recruits and to sell it to the masses

Only because people were desensitised; fear worked pretty well early on. They had to add in the nice bits later to entice back those who had figured out that God doesn't actually smite people, make floods, or diseases or plagues of locusts etc. because he isn't real and stuff. "Stick has broken, commence operation Carrot!"

I reckon someone just figured out that humans, over time, become increasingly defiant but remain steadily greedy.

"OBEY or bad things!"
- "Oh no, help! I will obey!"

"Continue to obey, or bad things!"
- "Nah, bored, come at me bro."

"Err... if you obey you get infinite sweets in heaven, really awesome ones."
- "...they free?"

"Yeah infinite! Free sweeties! You have to OBEY for now though."
- "Free... free sweets, you say? OK I'm back in."