Another Medieval Monday, and this time its disbelief, or complexity of belief, or some combination of the two. Because it's often hard to tell. The Middle Ages are often portrayed as the great Christian era in Europe, more religious than any time before or since. The Early Middle Ages included the spread of Christianity through much of Europe, the Central phase a defined Christendom able and willing to start to conduct Crusades while locally new monastic orders sprang up. And then there was a lot of business with putting down Heresy, the rise of the Inquisition in the Later Middle Ages and so on.
So it sounds like it wasn't the best of times to believe anything that wasn't orthodox, wasn't Christian, or just wasn't... well, believing. And yet, like anything when you're talking about more than a thousand years of history across a whole continent, it's a bit more complex than that.
For a start, the expansion of Christianity took time. Time, and its slow acceptance by more and more kings, who made it a criminal offence not to be. But that wasn't the same thing as making sure everyone believed. Bede notes plenty of "pagans" in his histories, although it's hard to pinpoint exactly what any of them believed. Later Chansons de Geste also seem to include them pretty regularly, suggesting that they were something people might have been familiar with. Certainly, there was the survival of non-Christian beliefs around the edges of places like Scandinavia and the north of Scotland. Then there was what we could think of as the Irish option, which was actually the everywhere option: the incorporation of pagan elements into local level Christianity. St Brigid (who used to be a Celtic goddess of that name) is an obvious one.
Then there's the point that Christianity was not some big, fixed thing through the period. It was a time, not of religious orthodoxy, but of experimentation and argument. The very fact that there were so many "heresies" suggests that. But so does the amount of tinkering that went on within the main church. It was only within the Middle Ages that the notion of purgatory really got settled in the Catholic Church, and the notion of the Pope as being in charge. A glance into the religious history of the times reveals a kind of constant argument, over everything from the right date for Easter (St Wilfred of Ripon got quite angry about that one) to Simony, Nicholaitism, the interaction of church and state...
And it wasn't like the results of these arguments filtered down to a local level quickly. This was not an era of mass communications. Many remoter areas had never seen a bible, and their priests certainly weren't up to complex questions on the finer details of faith, with the result that even nominally Christian areas could deviate considerably from the supposed norms.
So the Middle Ages weren't this big, fixed, ultra-religious monolith. They were something more complex, sometimes more dangerous, but where there were people who believed all kinds of things, or none.