European Christian communities responded immediately to World War I by tying up their national identities with their religious identities. Germans, Russians, the British and the French all used Christian rhetoric in promoting war efforts; some saw it as a righteous crusade for Christ, to save the world. But the war took millions of lives and was, as Pope Benedict XV described it, “the suicide of civilized Europe” (Jacobsen, 122). The hate-filled violence laced with religious zeal led many in Europe to question Christianity and a theology that could lead brother to kill brother. While a more humane theology emerged from several Christian pastors and scholars, average citizens were already too weary of the church and began separating themselves from religion in general. When World War II followed, religion played a very different role. Rather than Christian fervor promoting the war, fervor was sadly lacking in the protection of the Jewish people and minorities under Nazi threat. Reflections on both WWI and II, and especially the Holocaust, resulted in deep theological questions that endure to this day for many Europeans. Efforts to renew Christian thinking and practice were important but ultimately too little too late, and church decline in Europe continued significantly. Government-imposed secularization, known as Laïcité, contributed to this decline. France began enforcing church and state separation laws prior to the wars in 1905, and idea that spread in Europe in the postwar era. This resulted in a variety of national religious identities, including officially atheist nations (such as Albania) and communism. After World War I, atheist Russian leadership took disillusionment with the Christian church to an extreme and closed, destroyed, arrested or killed nearly all that represented Orthodoxy. This attitude toward Christianity spread post-World War II and communist countries frequently and oftentimes violently marginalized Christians (Jacobsen, 127).

In many ways, the increasing secularization of Europe has led to a decline in church. For instance, it is no longer socially acceptable to invite people to church in some areas. Christianity when practiced as other-worldly and overly spiritual does not fit in with the modern mindset of sensible practicality. In this way, it is understandable that Christianity has declined. However, some believe that while Europe has shed much of its religiosity, certain Christian values are actually increasing as evidenced in the Universal Declaration of Human Rights (Jacobsen, 130). Marriage and family size has also been steadily declining in Europe, and some see that as an additional threat to traditional Christianity, as fewer babies being baptized means fewer people are being born into a religion. Family structure looks differently than it did in the past, with those having children not always choosing to get married. Church ideals on family as being closely tied to morality in a community are conflicting with mainstream modern life, leading to questions on whether Christianity can adapt to this or not. Immigration to Europe has led to a rise in the Muslim population, challenging European secularization. It is yet to be seen if that challenge will result in further religious decline in the public sphere, or if it will spur a return for some to Christian belief practice. European Christianity is also being influenced by a huge influx of African and Asian immigrants, many of whom are Christian and are starting growing churches.

European Christianity has long held that reason and faith are intertwined. From Augustine of Hippo to Thomas Aquinas to Pope Benedict XVI, theology in Europe has had a rational and philosophical element to it. It is likely that this will continue and even increase as more and more Europeans seek university educations. In the same vein, science and theology are not outright opponents in Europe, but most tend to think that Christianity can (and should) be reimagined to fit with evidence-based science. In some ways, while secularism may seem a threat to Christianity, it does not seem to pose a problem for many Europeans who are deeply dedicated Christians – rather, their faith may be more flexible to accommodate modern ideas.

On the other hand, postmodernism questions whether the truth can be known at all (or if truth even exists). This is potentially a problem for Western Europeans who depended on reason, science and faith to successfully lead them to truth. Eastern Europeans who embrace Orthodoxy have less of a problem with this idea, as they have long believed that human ideas and reason could only attain a very limited view of God. According to many Eastern theologians, humans have limitations when it comes to understanding, and place a greater emphasis on immediate experience (Jacobsen, 143). Postmodern ideas will likely continue to jeopardize traditional Western theology, but if Western European Christians can allow flexibility to their faith (like they did with reason and science), then postmodernism does not need to be the “threat” some think it is. In other words, if the church can embrace their faith with humility and openness, it may look different than it has in the past, but can still offer hope to the changing world.