Ostensibly, religion was the foremost cause for colonization. Often times, the reason that was explicitly shared with royalty and members of the nations was that it was an evangelistic effort—to find and bring to repentance the indigenous natives. However, in reality, this was far from the case.

Simply analyzing the true actions of the majority of the settlers, and you can see that colonization was much more centered around economic profit than religious fundamentalism. When settlers came to new lands, they often killed (inadvertently or intentionally) the natives, took whatever resources they deemed valuable, and began a trade route back to Europe—which is how coffee, tomatoes, and many other important foods and goods came to the continent. The natives, who were apparently the main priority for the settlers, were frequently displaced and pushed away from the colonies so that they could focus on their own financial endeavors, because it was clear that they settlers cared little for the salvation of the "savages" and cared much more for their own profit.

While both religious and economic motivations were important to the settling of the North American continent, the economic driver was the more important of the two.

Admittedly, the extremely significant footholds the British formed in North American in the Massachusetts colonies and Pennsylvania were primarily, but not entirely, driven by the religious motivations of Puritans and Quakers to practice their faiths without persecution.

However, even religious settlements were financed by charter companies. These companies were owned by wealthy stockholders, usually aristocratic landowners, who invested—put up money—with the sole aim of making a profit from the resource-rich New World. Settlements, at least on the surface, were an attractive investment, as they promised the kind of steady profit stream that was hard to establish from random hunters, fisherman, or explorers bringing back raw materials from the rich continent on a sporadic basis. Therefore, even settlements of groups whose primary motivations were religious were made possible by the profit motive of the financiers back home.

In addition to the charter companies underwriting religious colonies for economic reasons, other colonies and settlements were established for purely economic and/or nationalistic reasons. Jamestown is a key case-in-point. The British wanted a permanent foothold in the Americas far enough away from the Spanish stronghold in Florida to be safe from attack, so as to establish a permanent economic base in North America. New Amsterdam was established as well for economic/nationalistic reasons, as were such French settlements as New Orleans, while Spain established permanent forts in the far west, such as in Santa Fe.

Catholic countries such as Spain and France also sent priests into the continent to convert native peoples, but there was little to no emphasis on the part of missionaries in creating permanent settlements.

Overall, economics was the chief driver behind the settlement of North America, though religion was also a significant factor.

There is evidence for both sides of this question and it is impossible to objectively quantify the evidence and claim that one set of concerns was clearly more important.

Some colonies were clearly settled more for one reason than the other.  For example, Massachusetts was clearly settled more for religious reasons than for economic reasons.  Virginia was clearly settled mainly for economic reasons.  But then there are colonies like Pennsylvania that was settled for a mixture of religious reasons and economic ones, with some people coming for religious freedom, others for economic reasons, and still others for a mixture of both.  Later, there were colonies like Georgia, which was settled as penal colony, that were not really settled for either of these reasons.

It is never easy to determine what human motives are most important in any given instance.  With the colonization of the British colonies in North America, there were many different groups of people coming for many different combinations of reasons.  Therefore, it is very difficult to argue that either religion or economic concerns was the most important factor.