Significado de "jam for the pill"

Olá, pessoal! Veja esse trecho:

The reader may perhaps conclude that certain features such as the dove, the voice, from heaven, and the adoption formula, "Thou art my son", ARE ALL SO MUCH JAM FOR THE PILL, designed to make it possible for Christians to stomach the unpalatable; but he will find it hard to shake the narrative framework.

Qual o significado de "ARE ALL SO MUCH JAM FOR THE PILL" nessa frase? O livro do qual essa expressão foi retirada é de 1967. Procurei o significado dess expressão e não achei.

My educated guess is that adding "jam to the pill" you sweeten the pill. Jam is sweet, and would leave the pill (more) palatable.

Jam - geléia. Something that normally is spread on bread.
https://i.ytimg.com/vi/42tqwhRlSWg/maxresdefault.jpg

http://idioms.thefreedictionary.com/sweeten+the+pill