In his book Inside Terrorism, Bruce Hoffman writes:
For the religious terrorist, violence is first and foremost a sacramental act or divine duty executed in direct response to some theological demand or imperative. Terrorism thus assumes a transcendental dimension, and its perpetrators are consequently unconstrained by the political, moral or practical constraints that may affect other terrorists.
Whereas secular terrorists, even if they have the capacity to do so, rarely attempt indiscriminate killing on a massive scale because such tactics are not consonant with their political aims and therefore are regarded as counterproductive, if not immoral, religious terrorists often seek the elimination of broadly defined categories of enemies and accordingly regard such large-scale violence not only as morally justified but as a necessary expedient for the attainment of their goals. Religion conveyed by sacred text and imparted via clerical authorities claiming to speak for the divine - therefore serves as a legitimizing force. This explains why clerical sanction is so important to religious terrorists and why religious figures are often required to ‘bless’ (i.e. approve or sanction) terrorist operations before they are executed.
Religious and secular terrorists also differ in their constituencies. Whereas secular terrorists attempt to appeal to a constituency variously composed of actual and potential sympathizers, members of the communities they purport to ‘defend’ or the aggrieved people for whom they claim to speak, religious terrorists are at once activists and constituents engaged in what they regard as a total war. They seek to appeal to no other constituency than themselves. Thus the restraints on violence that are imposed on secular terrorists by the desire to appeal to a tacitly supportive or uncommitted constituency are not relevant to the religious terrorist.
Moreover, this absence of a constituency in the secular terrorist sense leads to a sanctioning of almost limitless violence against a virtually open-ended category of targets: that is, anyone who is not a member of the terrorists’ religion or religious sect. This explains the rhetoric common to ‘holy terror’ manifestos describing persons outside the terrorists’ religious community in denigrating and dehumanizing terms as, for example, ‘infidels’, ‘dogs’, ‘children of Satan’ and ‘mud people’. The deliberate use of such terminology to condone and justify terrorism is significant, in that it further erodes constraints on violence and bloodshed by portraying the terrorists’ victims as either subhuman or unworthy of living.
Finally, religious and secular terrorists also have starkly different perceptions of themselves and their violent acts. Where secular terrorists regard violence either as a way of instigating the correction of a flaw in a system that is basically good or as a means to foment the creation of a new system, religious terrorists see themselves not as components of a system worth preserving but as ‘outsiders’, seeking fundamental changes in the existing order. This sense of alienation also enables the religious terrorist to contemplate far more destructive and deadly types of terrorist operations than secular terrorists, and indeed to embrace a far more open-ended category of ‘enemies’ for attack.
The primary factors which differentiate religious from secular terrorism can also serve to make religious terrorism much more dangerous. When violence is a sacramental act rather than a tactic for achieving political goals, there are no moral limits to what might be done — and seemingly little chance for a negotiated settlement. When violence is designed to eliminate an enemy from the face of the earth, genocide can’t be far behind.
Of course, just because such nice and neat categories exist in academia doesn’t mean that real life must necessarily follows suit. How easy is it to differentiate between religious and secular terrorists? Religious terrorists may have identifiable political goals that they might negotiate for. Secular terrorists might use religion in order to gain more followers and inspire greater passion. Where does the religious being and the secular end — or vice-versa?