The origins of Human Religious Behavior
Throughout the history of psychology, the topic of human religiosity has been referred to as a learned behavior. In other words a person's religion is the final outcome of the person's interaction with his environment. Therefore the assumption is that if you are born in a Christian country, you are going to be a Christian.
Theoretically, since the person has been exposed to his religion from early childhood, it would be quite unlikely that he would choose a different religion or have the desire or the need to practice something else. Although, we do see occasional cases of conversion of single individuals from one religion to another religion, mass conversions are usually rare and mostly are caused by wars and force.
Although, the followers of great religions of the world do not like to admit this historical fact, an honest historian would admit that my ancestors' conversion from Zoroastrianism to Islam was only achieved by sword.
The same is true for natives of South America becoming Christians. Their faith was sealed by Spaniard swords.
Interestingly, the forceful attempts to make a population atheist have never worked. The most famous historical example of these attempts is Stalin's brutal confrontation of religiosity. Stalin did not look at religion as just "opium of the masses" he looked at it as a menace for the society and considered clergymen as parasites. Stalin's method of dealing with religion was the same method that he used in dealing with anything... elimination. His answer was total elimination of religion. He ordered all mosques, churches and temples to be burned, as well as the killing of all clergy.
It should be noted that upon the collapse of the Soviet Union the first changes included reappearance of mosques, churches, temples and clergymen.
In other words you can force people to convert to a different religion, but you cannot force them to become an atheist, as if they can not live with out it.
The Case for the Organic Nature of human religiosity.
The idea of hereditary causes of human religiosity was originally introduced by Charles Darwin. This idea is articulated in his autobiography:
conclusion was strong in my mind about the time, as far as I can
remember, when I Wrote the Origin of Species; and it is since that time
that it has very gradually with many fluctuations become weaker. But
then arises the doubt
can the mind of man, which has, as I fully believe, been developed from
a mind as low as that possessed by the lowest animal,be trusted when it
draws such grand conclusions? May not these be the result of the
connection between cause and effect, which strikes us as a necessary
one, but probably depends merely on inherited experience? Nor must we
overlook the probability of the constant inculcation in a belief in God
on the minds of children producing so strong and perhaps an inherited
effect on their brains not yet fully developed, that it would be as
difficult for them to throw off their belief in God, as for a monkey to
throw off its instinctive fear and hatred of a snake".
Charles Darwin, Autobiography,1887
It is known that Darwin personally delayed publication of his "Origin of Species " by twenty years. The cause of this delay was not his fear of the response to his introduction of the theory of evolution, rather, he feared the response to his assertions on the organic nature of human religiosity, which was totally unacceptable at that time. It should be noted that 1250 copies of the first edition of "the origin of species" was published in London; all 1250 copies were sold on the first day.
The evidences for organic nature of human religiosity
There is a general rule in psychology that universal behaviors have organic causes. And consequently their origin could be traced to human brain. For example all human beings manifest sexual behavior as well as aggression. These behaviors are seen universally, in all cultures at all times.
Therefore, if one runs into a person who is totally devoid of sexuality or aggression, .One can assume that the person is suffering from some kind of disease or condition. If one examines the human brain one can easily locate those parts of the brain which are in charge of sexual and aggressive behaviors. At the same time if one cannot locate the original site of a universal behavior it does not mean that the behavior does not have an origin in the human brain. It just means that one does not have the instrumentation or the knowledge to find it.