I have been visiting some old country houses which were inhabited by Roman Catholic families during the period of the 1500s and 1600s when it was uncertain whether England was to be Protestant or Roman Catholic.
These contained 'Priest holes' - concealed chambers and escape routes for hiding Priests - Jesuits, or 'secular' Priests trained abroad and monks.
The accounts of the times are astonishing for the devoutness exhibited on both sides, also for the hatred and horrific cruelty of persecution on both sides.
But this was in fact war, and that fact does explain the relentlessness of the persecution.
It was a cold war, mostly - but the punishment of Catholics was mostly motivated (at the political level) by the fear of treason, and this fear was very real.
There were of course plots and plans to kill monarchs, and/or to assist foreign invasions - and this kind of thing does tend to elicit aggressive responses.
And there must have been extraordinary psychological conflicts between patriotism and religion.
Most obviously, for Roman Catholics, between the natural desire to have England ruled by the English and with the English way of life; and the desire to restore Roman Catholicism, even at the cost of becoming a conquered nation.
On the other side, the Anti-Roman and Protestant side were responsible for smashing and looting the English way of life - including schools, hospitals and crafts - through the vast destructiveness of the 'dissolution of the monasteries' era under Henry VIII, and the later iconoclasm of the Puritans at the time of the Civil War.
The modern 'reaction' against religious wars has buried 'religious differences' under the imperative of hedonic, distracting Leftism - and the iconoclasts and appropriators have joined forces with the traitors and sponsors of invasion.
In modern England, nobody cares enough to 'sacrifice' even a couple of hours on a Sunday to attend Church - never mind risk torture and execution for beliefs.
As for cruelty and persecution - for the modern English, it all depends on who is being persecuted and who is inflicting the cruelty.
The authorities do not at present tear people apart judicially, as happened to Nicholas Owen, the master carpenter who travelled England making priest holes; on the other hand they tolerate, excuse and actively conceal and lie-about murder and mayhem on a large and growing scale. (This has been re-labelled as tolerance and equality.)
Destruction of beauty is still a state-sponsored activity (but re-labelled as 'art'). Propaganda against ideological enemies is now called 'science'. Immorality is re-labelled as a higher form of virtue, or as disease, and promoted with cash and kudos - both actively and indirectly.
And rather than two profound imperatives leading (at times) to excruciating conflicts; to be strongly anti-English and zealously anti-Christian is regarded among the ruling class as quite simply admirable.
...The difference is between a Christian elite and an elite who 'believe in' nihilism.