Is the spreading of Islam or Christianity outside their country of origin more political and economical in nature than simply a matter of faith? Is any spirituality associated with it? How would you explain forced conversions into Islam and Christianity in the past?

Faith is of the heart. Religion, if you will, in that it is organized, is more like a club with rules – these are my own working definitions, at any rate.

Supposing these definitions have merit, recall that forced conversion to a religion has been documented throughout history. Between the fourteenth and twentieth Centuries CE the Catholic Church did its best to drive out ‘false’ beliefs e.g. Judaism. Currently China is doing what it can to drive out Christianity.

The Muslim faith actually makes all other faiths illegal, and between its inception and its maximum extent it spread itself by military conquest.

Were the many spreadings of a religion economic and political more than religious? To answer that, do we need to distinguish between faith and a club with rules?

One misfortune of the Spanish just after driving the last Muslims off their peninsula near the end of the fifteenth Century was to turn on the Jews and drive them away also. But, alas, Jews were the engine of commerce in that they facilitated the flow of money. They would lend it out. Without Jewish participation in national commerce, Spain withered. Plundering the New World kept Spain afloat, but they blew it all on the great Armada of 1588. After that escapade, Spain faded from the front ranks of commerce, influence, etc.

It took until 1820 for the Mexican government to become independent of Spain. During the second decade of the 19th Century Simon Bolivar helped the Spanish colony/nations of South America divorce the Spanish Government. So it took a while for Spain to fall flat; but fall it did, arguably due to expelling the Jews.

In other words actions taken at the level of nations which have primarily doctrinal underpinnings bring an unreliable “bottom line.” Beware of the Law of Unintended Consequences. The 21st Century world has replaced faith with science, and as a consequence forced conversion into or out of any given faith system has lost its economic importance hence just doesn’t happen, and we’ll see whether the religious hold-outs who conflate science with perversion of their faith systems manage to drive their nations onto similar shoals.

Unless you’re akin to Boko Haram, and feel that your religion is the primary rule of public action as a system of laws.