It’s beyond established that the Catholic Church dominated law, custom, culture, and life in Europe for a thousand years. In those days, were the masses expected to attend, uh, mass, every Sunday, on pain of some kind of punishment? If you decided to skip mass some Sunday, could you expect a visit from ecclesiastical authorities the next day? How about if you ditched it consistently and for months? What about if you kept your children at home with you?
The answer is going to vary by locality and date.
This article about the English Catholic Church in a British magazine suggests church attendance every Sunday was expected but hard to enforce.
In practice, making people attend church was difficult. A priest could refuse to hear their confessions or report them to the church courts where they might be fined or made to do public penance, but it was a long-winded process. There were always some people in a parish who did not go to church very often. Attending church on Easter Sunday was absolutely compulsory for all adults, however, so almost everyone would have been there on that festival.
The same article said they also had to make allowances for some professions, such as fishermen and servants, who often had to work on a Sunday.
It wasn’t just mass on Sunday. The Catholic calendar was full of holidays dedicated to the various saints; depending on the region, the total number of holidays, including Sundays, could be more than 100, so about one in three days would be a religious feast of some sort. There surely was an expectation to attend mass on those or participate in whatever celebration was customary for the particular holiday, but the enforcement mechanism would be more something of social peer pressure - in villages, where everybody knew everyone else, absence would be immediately noticed; but even in cities, which were organised along parish lines, your usual social circle would notice if you’re not there. I doubt, however, that the church authorities would use formal enforcement mechanisms such as fines for non-attendance; things would have been different, however, for violations of the prohibition to perform work on a holiday - those rules were more strictly enforced.
Likewise, after the Reformation, there were fines for those who failed to attend Church of England services, for quite some time. And after the Pope encouraged the idea of murdering Elizabeth I, Catholic priests and those who sheltered them were pursued as traitors.
Similar to @PatrickLondon’s point, Protestant Geneva was a theocracy. Michael Servetus fled there thinking to find freedom of religion, but was burned at the stake for heresy after John Calvin denounced him.
According to Voltaire, “If they [Luther, Calvin, Zwingli] condemned celibacy in the priests, and opened the gates of the convents, it was only to turn all society into a convent. Shows and entertainments were expressly forbidden by their religion; and for more than two hundred years there was not a single musical instrument allowed in the city of Geneva. They condemned auricular confession, but they enjoined a public one; and in Switzerland, Scotland, and Geneva it was performed the same as penance.”
The pre-Reformation ecclesiastical courts across much of Europe did have powers to punish non-attendance, up to and including excommunication. But the ecclesiastical courts tended to be weaker than the secular courts and their willingness to enforce their rules varied enormously. Non-attendance prosecutions were usually rare, except in extreme cases or where other issues were involved. This was why after the Reformation some Protestant countries and communities made a point of strengthening the rules. That sometimes involved making it a secular offence over which the secular law courts had jurisdiction. But even then enforcement was often patchy.
When I read of these “enforced” re;ligions I always think back to my father-in-law (may he R.I.P.) who would say:…"Thats why our forefathers and foremothers came over here! To get away from all that crap!" (exact quote)
True for some, but others came here to impose their own religious rules. New England, starting with Plymouth, was terrible for nonconformists, which led to splitters founding Massachusetts, Rhode Island, and Connecticut.
In the modern Church, there’s still the concept of “holy days of obligation”, on which all Catholics are supposed to attend mass (though of course, there’s no enforcement of that any more). But the modern list consists of only ten: Christmas, Epiphany, Ascension, the Body and Blood, Mary Mother of God, Immaculate Conception, Assumption, St. Joseph, Sts. Peter and Paul, and All Saints. And of course, in any given year, some of those can fall on Sunday (and when they fall on a Saturday, the obligation might be shifted to Sunday), so the total for the year is usually less than 62.
It seems it only mattered significantly when absence was seen as making a statement - not just Catholic vs. Protestant, but those like Puritans or non-conformists who opposed the form of the Church of England. Barbra Tuchman quotes a bishop in A Distant Mirror complaining (in the 1300’s) that someone had told him humans were like animals, and when they died that was it, there was no soul, no heaven, etc. That sounds like a fairly lax level of enforcement of church orthodoxy. I assume like many other political crimes, it could be invoked against opposition when it was necessary to “teach someone a lesson”. I suppose, like treason in civil law, the only real heresy that attracted the full force and power of the church was denying the power of the church hierarchy.
There seem to be a lot of laws in the “Goode Olde Days” that were arbitrarily enforced.
These same accusations probably don’t make sense applied to Luther. Luther after all wrote a number of hymns and asked that singing be taught in schools… and was a brewer (though he said Katie’s beer was the best).
Luther: The Musician | Christian History | Christianity Today
(which features the fantastic Luther quote: "Next to the Word of God, music deserves the highest praise. … But any who remain unaffected [by music] are clodhoppers indeed and are fit to hear only the words of dung-poets and the music of pigs.”)
Lutheran Germany was very different than Calvin’s Switzerland.
A parallel might be with life under various, not necessarily religious, totalitarian regimes in modern times. Religion was the state, not a discretionary thing like organised sport that you could choose to ignore. Everything that you did or did not do was interpretable as a positive, negative or neutral response to the state.
In most totalitarian regimes they quickly give up on having everyone believe, and settle for doing as you are told. When the Church is the pervasive power what seem like innocent actions to you, might be seen as big threats or challenges to power to them. You might even get inquisited if you persist in being a loudmouth about having a Sunday lie-in.
‘Occasional Conformers’ denoted those (usually Dissenters) who attended the most important Church of England services to the minimum necessary to avoid prosecution.