Matrimonial devotion doesn't seem to suit her notion.

Things are seldom what they seem.

Things are seldom what they seem, / Skim milk masquerades as cream.

I believe that many who find that "nothing happens" when they sit down, or kneel down, to a book of devotion, would find that the heart sings unbidden while they are working their way through a tough bit of theology with a pipe in their teeth and a pencil in their hand.

What this means is the suit will not go on for 20 years,

Suit the action to the word, the word to the action