I might just advertise a long post here which is on the conversion and therefore somewhat related.

Anyway, first off is the fact that the Viking Age is a rather artificial construct since for starters its defined from an external point of view; typically from the raid on Lindesfarne to the Norwegian defeat at Stamford Bridge. So right there it's hard for it to be a good indicator of Scandinavian culture, since it's not really in Scandinavian terms. The era is diffuse on both ends. Some of the cultural changes that we'd associate with the Viking Age, such as the rise of towns/trading posts/birks began earlier, with Hedeby being founded at the start of the 8th century, and Birka in the later part of that century. The fairly recent discovery of the Salme ships (early 8th century) in Estonia show that raiding abroad also began earlier than thought previously.

Many cultural aspects that people associate with the Viking Age continued long afterwards. The Urnes Style, one of the most iconic 'Viking' styles really only started in the last decades of the Viking Age (by whichever standard) and continued through at least the first half of the 12th century (when its namesake church was built). The style did not suddenly disappear but mingled with Romanesque styels from the continent (again the stave church is an example of that) Scandinavians continued to travel to Miklagård/Constatinople and serve in the Varangian Guard for at least another 150 years after the Viking Age. The erecting of runestones ended in the early 12th century as well, not due to Christianity - in fact most runestones were raised by Christians - but more likely due to people beginning to bury their dead in churchyard cemeteries. The runic writing system continued to be used (and develop) for as long after the Viking Age as the length of the age itself. In certain locales (e.g. Gotland) it was used even longer and in Dalarna it continued until the 20th century.

Same thing goes with conversion; that was a process that took a century and a half at least. Christianity started making inroads in the nobility/elite in Denmark in the 10th century, the fairly recent discovery of Kata Gård in Sweden shows the same applied to the Götar (Geats) even if the Svear (Swedes-proper) did not convert until the 11th century. Vikings were more Christian than the population at large, as it was precisely when abroad, whether in England or Byzantium, that they were coming in contact with Christians. Missionary activity came later (except the famous yet failed mission of Saint Ansgar), although there is a lot we don't know about that. (especially about the English and Irish missionaries)

In other words, conversion alone could not be said to be the reason they stopped raiding abroad, as they clearly didn't. A pet example of mine is the Ingvar Stones, memorializing those dead on the disastrous journey of Ingvar the Far-Traveled. (c 1030) Out of those nearly 30 stones, making it an unusually well-documented event, most are explicitly Christian, while none are explicitly pagan. (although as I said earlier, the pagans were erecting fewer stones in general)

Or one could also point to the fact that the very Viking king who was defeated at Stamford Bridge, Harald Hardråde was himself a staunch Christian who worked to promote the religion in his kingdom. Danish attacks on England were also made even later in 1069, which is 'technically' after the Viking Age. In short, Christian faith was not a deal-breaker at least as far as conquest went. (attacking monasteries like Lindesfarne would most likely be off the table though)

That was not necessarily the end of foreign raids, though, considering the raids that Denmark and Sweden began making against their pagan Finnic, Baltic and Slavic neighbors, as 'crusade's in the 12th century. The Wendish crusade where the Danes sacked and burned the temple at Cape Arkona on Rügen, under direction of Bishop Absalon, was supposedly a retaliation for the Wends raiding Denmark.

So the problem here is that to answer the question of "why did the Viking Age end" or "how did Christianity end the Viking Age" one has to come up with a defining characteristic for the Viking Age, and that is difficult. There were gradual changes that occurred over a long time, and at different rates in the 4-5 countries involved.

I'm not sure where these themes come from. Regarding monogamy: most Scandinavians already were monogamous during the Viking Age, although the aristocracy/elite would have concubines or female slaves used for sex. But female concubinage among the elite continued well into the Middle Ages (then being termed a frilla/frille). (also marriage wouldn't become a sacrament until the Synod of Verona in 1184)

Regarding centralization, there was a certain amount of consolidation of power during the Viking Age. The aforementioned Harald Hardråde managed to crush local opposition and make himself king of all of Norway. Olof Skötkonung of Sweden is the first to be described as king of all of Sweden (including Götaland). However that does still not amount to anything resembling a strong central government. On the contrary, Denmark, Sweden, Norway and even Iceland became embroiled in civil war from the mid 12th century to the mid-13th. All those wars largely amounted to the kings allied with various constellations of nobles fighting other alliances of nobles, some of whom were also allied with foreign kings. And the driving source of friction was largely the matter of the strength of the monarchy relative the aristocracy. The outcomes of these feuds was quite different in different countries too.

In short though it's not at all wrong to say that Christianity brought the end of the Viking Age. The religion itself played some role there, but not necessarily the main one, because there was also a multitude of social and cultural changes that took place due to it, even if those changes occurred over multiple generations. I can't really decide for you what to focus on, but perhaps the literature can.

To list some quality books on the Viking Age in general and the conversion and end of it in general:

Brink, Stefan, The Viking World, Routledge, 2011

Jones, Gwyn, A history of the Vikings , Oxford University Press, 2001

Berend, Nora (ed), Christianization and the Rise of Christian Monarchy Scandinavia, Central Europe and Rus' c.900–1200, Cambridge University Press, 2009

Sanmark, Alexandra, Power and conversion : a comparative study of Christianization in Scandinavia , Uppsala: Dept. of Archaeology and Ancient History, 2004 (on academia.edu)

Sawyer, Birgit; Sawyer, Peter, Medieval Scandinavia : from conversion to Reformation, circa 800-1500 , Univ. of Minnesota Press, 1993

(If you can read Scandinavian languages I could rattle off a few more too)

(Edit: Wow, this post was way longer than I thought)