I think human beings are not moral by nature and the assumption that we are can be a big danger when different cultures mix.

I am currently working on this topic. However, I am still not in a position to articulate my thesis in proper frames. But, some basic facts that are very obvious are casually listed as under: 

(i) In human history, more lives are lost because of religious issues than secular.

(ii) Most heinous criminals are often found to be most religious and devoted one.

(iii) One justifies his action, even though it is very immoral or inhuman, only in the name of his own personalized religion. 

(iv) A religious mind is always an opportunistic mind. His every action, whether ethical or unethical, moral or immoral, good or bad, is enacted only for his interest for gaining religious merits. This, in fact make him more cruel in real sense, compare to any rational/secular minded person.

(v) A secular person always act predictably. If he is altruistic or ethical, he is so without any interest, and therefore, he is more moral in real sense.

(vi) Minus religion, human beings will still remain moral because they have to live in the society from which they would expect similar kind of behaviors. This will be the general or average trend.

(vii) A small minority percentage of people will always remain immoral/opportunistic irrespective of religiousness or secular existence.

Dr. Babul Roy, India.

Religion is a structure that was created by the human mind and is not the energy or prana that connects and sustains us.

Absolutely correct. In that spirit, religion is universal. A spirit that inspires us to do something good for us and for ourselves. That spirit, that universal religion will hardly differentiate 'religion' from 'religion' dividing us into different conflicting groups. Yes, in that sense, humanity will never be without a religion. Such a religion will ever remain transcendental and universal across all human beings. However, by the term 'religion' as I mean in this Question is not about that universal religion.     

yes, it's a matter of definition, namaste Babul

From the religious perspective (with possible extensions in philosophy, see Kant), human beings are morally natural.

From a scientific (ethological view, see K. Lorenz), on the contrary, human beings do not have the instinct to protect other human beings.

But, Human rights and Western democracies are a consequence of Christianity.

Sorry, I am not fully agree with Daniela Sorea. Religion is ethical is much later development in human history. In basic tribal religion, the religion, i.e. the belief system, often does not endorse the morality or the ethical domain of their life, at least directly. But, in tribal society, the people are still moral and ethical as per the tribal norms. They are so, not because of their fear in religion but, because of their togetherness in the society.

Universal religion nicely described by Indian poet Rabindranath Tagore in several of his verses. One of his verses (translated in English) in which he has denounced all the major forms of structured religions, but endorsed the basic instinct of human beings what according to him is the true religion. I am reproducing it here under:

Prayer, worship, meditation,

Leave everything sideways.

Why you are in the corner of a closed door temple,

Whom you are secretly worshiping – 

On your own, hiding in darkness

Open your eyes,

Look! There is no god in the room.

He has gone

Wherethe peasant tilling his land – 

Labourers making path

Bybreaking stone.

Toilinghard round the year.

He is with everyone toiling,

Under the sun and in rain.

Dust stained his both hands – 

Come to the dust like him

Leaving clean comfort behind.

Emancipation, 

Where to get emancipation,

Where there is emancipation.

God himself is bound with us all

With the bond of creation.

Keep aside mediation,

Leave aside the flower basket.

Let the clothe spoiled

With stain and dust.

Let us united with him

In the spirit of work,

Leaving religion

Withered behind.

From Tagor's Geetanjali (Translated by Dr. Babul Roy, New Delhi)

Thanks Juliet E. Morrow, This is really good point that religion is a structure that was created by the human mind and is not the energy or prana that connects and sustains us.

Dear Babul Roy, 

I believe that structured religions are culturally determined expressions of this instinct ("God himself is bound with us all

With the bond of creation."-Tagore said). People have not invented the connection with God, people just gave them different expressions.

Perhaps there is the source of moral behavior. Primitive societies had their moral laws, even if these laws do not conform to our moral laws.

(There are two kinds of instincts here: Tagore's instinct and

Lorenz's instinct.Lorenz says that human beings do not have the animal instinct to protect other members of the species, and that the survival of the human species depends on its wisdom.)

Many Thanks Daniela Sorea for your enlightening comments. "Primitive societies had their moral laws", I do agree with that. But, my thesis is that to what extent the moral laws in primitive communities are backed by religious sanction. There could be a hotted argument on this issue, because all such communities do not live at the same platform/ status of existence. There are communities in which the religious fear for violating tribal norms is obvious, while there are others where the tribal norms and the supernatural beliefs are not well connected. In fact the supernatural beliefs have either no or very little/ indirect connections with the tribal morality. But, still the people behave according to their tribal norms and values. (My studies among Zeme Naga is an example) Here their behavior is not due to their fear in religion. What I mean is that the religious control of human morality is a later historical development, very clearly established in our great religious traditions as we have today.    

Human beings are good, i.e. moral by nature (irrespective of any religious sanction), and that is why when a preacher teaches a good moral lesson, he immediately gets his followers. This is the basic reason that a religion has established in human society. But, unfortunately a minority of the people who are immoral and opportunists by default take the name of religion to play their narrow game of politics for some or the other vested interest. 

Religion emphasizes healthy morals. However, there is a religion that is not dependent on the truth causing moral behavior to be incomplete. The result is that thoughts are contrary to the nature of good human nature.

Religion instills a sense of "creatureliness" that would not be there otherwise, and this is, I believe, a moral virtue.  Perhaps a non-religious person would have an analogous sense that could be expressed in less religious terms.  And, of course, not all nominally "religious" people possess that sense.