One thing was noticeably not present for the first time in Greece's history when ultra-Leftist Alexis Tsipras was sworn in on Monday as that nation's first atheist prime minister — a Bible.

Instead of taking the traditional biblical oath of office, the left-wing party victor in Greece's elections insisted on taking a civil oath, according to Reuters — refusing to take part in the religious ceremony that his predecessors have participated in for decades on end.

But this shift from Christian values and from a willingness to uphold biblical principles in leadership is becoming a more pronounced trend throughout Europe of late, The Christian Post reports. Within the European Union (EU) at least two other nations are being led by politicians who have made public proclamations identifying themselves as atheists, according to a Quartz survey analyzing statements given publicly by leading European politicians divulging their beliefs.

Like Greece, France and Croatia have also recently installed atheistic politicians to lead their nations — departing from the religious heritage of leaders from those nations in the past.

Croatian Prime Minister Zoran Milanovic has been recorded stating his atheistic beliefs, while French President Francois Hollande says he has no religion, despite being raised in a Roman Catholic home.

"I have reached a point where what is clear to me is the conviction that God doesn't exist, rather than the contrary," Hollande said about his beliefs back in 2002.

However, it is also noted that Hollande, at one point, remarked that he respects all faiths, indicating that he has made the personal decision to not have one of his own, according to Quartz.

Becoming the trend, but not the norm … yet

Even though Tsipras', Hollande's and Milanovic's coming out as atheistic politicians is not as uncommon as it's been in the past, many still consider such a move to be very risky politically. Quartz disclosed that with the majority of the European population ascribing to some form of Christianity, it is still very rare for the leader of a nation in the EU to declare publicly that he or she has no personal belief in God or religion.

In America, mixing faith and politics hasn't been nearly as taboo as it has been in Europe over the years, where many believe bringing up one's religious beliefs can be risky toward one's political career.

Even so, two leaders in a couple of the European Union's most prominent nations, the United Kingdom and Germany, have referred to their Christian faith during speeches and public statements throughout the years.

British Prime Minister David Cameron hasn't been shy to profess his strong faith in God in speeches. Last Easter, Cameron emphasized his firm belief in the Bible on three occasions, professing himself to be an "evangelical" Christian.

German Chancellor Angela Merkel has also unabashedly proclaimed her religious beliefs. "I believe in God and religion is also my constant companion, and has been for the whole of my life," she proclaimed, referring to her Christian beliefs.

But other leaders of European nations aren't as secure in their religious convictions, according to the analysis taken by Quartz — which was used as a spiritual barometer for the EU.

Swiss President Simonetta Sommaruga announced earlier that she has left the Catholic Church, but that she is currently "searching" to find her ultimate "religious path."

When the topic of his personal faith was brought up in public, Slovakian Prime Minister Robert Fico declined to speak about the issue after initially proclaiming himself to be an atheist — only to later call himself a Catholic.

EU faith number crunch

With much talk commonly circulated in recent years that the EU is comprised mostly of post-Christian societies, a 2010 Eurobarometer Poll was administered to find its true spiritual temperature. What researchers found was that different nations within varied widely.

When pollsters launched their study, they gave members of the EU three different responses to choose from to describe their personal faith: (1) "faith in God," (2) "faith in some sort of spirit or life force," and (3) "no faith in any God or life force." Here is what they found:

Ranked far ahead of any other European nation when it comes to their faith, 94 percent of the citizens of Malta declared that they have faith in God.

At the other end of the spectrum when it comes to their faith — or lack of it — were the people of the Czech Republic. Only 16 percent of the residents of that nation proclaimed they have a faith in God — the lowest in all the EU.

Joining the Czechs toward the bottom when it comes to their faith in God were the French. Just a little over a quarter of the residents of France (27 percent) believe in God. At the same time, the French registered the highest numbers in the poll when it came to those indicating that they did not believe in God or any other "life force" — 40 percent.

It was a different story in one of the other countries in the EU that voted for an atheist national leader. Not reflective of the atheist prime minister they selected in their recent election, 79 percent of Greeks surveyed indicated they have a personal faith in God.

When all is said and done, there might be some truth to the assertion that the EU is — for the most part — a conglomeration of post-Christian societies, as the Eurobarometer Poll demonstrated that just more than half (51 percent) of residents from the European nations indicated that they have a faith in God. With many Muslims and people of other religions also claiming a faith in another god, one can conclude that the number of those believing in the God of the Bible is clearly under half of all EU residents.

Moving along, a little over one in four EU residents (26 percent) marked that they believe in some spirit or life force. Atheists comprised the smallest of the three groups, as 20 percent of those residing within the EU nations declared that they do not ascribe to any faith.

But, even though most consider Europeans to be less religious than Americans — as many conservatives constantly fear that U.S. courts will adopt more progressive European laws in its courtrooms — a 2012 Pew Poll showed that the percentage of people from both populations not believing in God on either side of the Atlantic is equal.

As it turns out, 20 percent of Americans now consider themselves to be atheist, agnostic or unaffiliated with a religion, according to the Pew Research Center's Forum on Religion and Public Life — indicating a decline in religious adherence and an increase in secular worldviews of adults in the U.S.

The two polls show that Europe and America aren't as different as many think.