I was just so daunted at the prospect of summarising their moral differences, that I stuck to the practical side.

For me, the passage in MP which really shows the difference between the religious and the (effectively) non-religious people is Fanny's reaction to Tom's illness:

"Without any particular affection for her eldest cousin, her tenderness of heart made her feel that she could not spare him, and the purity of her principles added yet a keener solicitude, when she considered how little useful, how little self–denying his life had (apparently) been."