What are common characteristics to religious nationalism?

I am not completely confident of how you would define
religious nationalism. Let me give you the definition I would use and
answer the question based on that definition. If I have missed the mark,
please rephrase your question so that I can be sure how you would define
religious nationalism.

I would define religious nationalism as a political situation
in which a nation or a sovereign government sponsors in some way an
official national church. This phenomenon is by no means restricted to
“Christian” countries. In fact, it is more prevalent in countries which
support non-Christian religions. Obvious examples would include the
dozens of nations which have Islam as their national religion. This would
include Algeria, Tunisia, Libya, Egypt, Saudi Arabia, Pakistan and so
forth. In many of these countries non-Muslims are very much persecuted
and are prevented by law from taking part in the government, from
proselytizing and so forth. Not all predominantly-Muslim countries
exhibit official political nationalism. For example, Indonesia, Turkey
and (believe it or not) Iraq have officially secular government. Another
borderline case is India which has an officially secular government, but
when it is controlled by the BJP (as it is now) it leans strongly toward
being an officially Hindu country.

Official religious nationalism in the “Christian” parts of the
world varies by degree immensely. For example, Great Britain is formally
an Anglican country, with the king or queen required to be Anglican and
with the government supporting some Anglican institutions with tax
money. However, religious nationalism is quite benign in Great Britain.
It is easily ignored by the populace. Russia has its national church,
known by Westerners a Russian Orthodox. In this case, official government
support of the church is a significant political fact in the country. And
then, there are a number of countries which are either officially
supportive of Roman Catholicism, or have the Roman church so predominant
as to make the fact that the government is officially secular be almost a
moot point.

That was a long introduction before I get to answering your
question. The fact is that the characteristics of religious nationalism
will vary to a very great degree. Historically, religious nationalism is
created out of a complicated mix of religious conviction and political
expediency. In the case of Christian history, the process of creating
Christianity as a national religion in Rome began with Emperor Constantine
in about AD 324. The writings of Augustine of Hippo in the late 400’s AD
provided the theological justification for the cooperation of church and
state. From that time forward, the state became both the arbiter and the
promulgator of religious orthodoxy.

The effect of such a political cooperation between a
particular religious group and a national government is fairly easy to
predict. As the saying goes, power corrupts, and absolute power corrupts
absolutely. History tends to show that when a particular religion, or
more specifically when one particular sect of a particular religion
obtains political power and sponsorship, that religious movement tends to
become corrupt, both religiously and politically. When an entire populace
is pressured to ascribe to a particular belief system, it tends to dilute
the level of conviction and purity of the members of that religious
group. It is hard to think of an historical example which does not
support this thesis. Deep, personal religious conviction tends to blossom
in a situation in which those who are devoted to a particular belief are
either left free to decide their convictions or, perhaps surprisingly,
when they are persecuted for their beliefs.

To finally answer your question, the common characteristics of
religious nationalism, are;

1. government support through use of national funds to support the clergy
of that religion.

2. pressure on the government to support the moral and ethical beliefs of
that religious groups.

3. attempts by the government to suppress other religious groups. (the
extent of this varies a lot from case to case)

4. a tendency for the clergy of that religion to become corrupt and for
devotion and depth of conviction of adherents to that religious group to
diminish with time.

These are the chief symptoms I see from my study of history.

John Oakes, PhD