There is a tendency to think that ‘ethics’ have a religious basis and must be firmly explained in the form of God’s commands- “Thou shall ” or “Thou shall not". When a fundamentalist carries out an act of terror, he genuinely believes that he is an ethical human being, adhering to laws prescribed by his God.
Religion and ethics need to be viewed separately.
Ethics, to apply Darwinian logic, is a product of natural selection. By laying a proper framework for social relationships, it confers a survival advantage on our species. As this essay explains:
We became fully human when we were able to find ways of inhibiting tendencies to socially disruptive action and ways of reinforcing our altruistic capacities. Practices of punishment may well have played a role at early stages of the process. The crucial step, however, consisted in internalizing the check on our behavior. We became able to formulate rules for ourselves, or to remind ourselves of exemplary cases of conduct: we invented a crude system of ethics.
Thus it is that societies such as ones in Scandinavia that are pre-dominantly atheistic have a well-developed ethical framework to act as their moral compass. Their commitment to protecting the environment or in adhering to a clear code of conduct in the public space emerges from this moral compass.
As Dawkins has explained, religion was an unintended byproduct of human evolution, and is completely anachronistic now. The sooner we abandon it, the better. The word ‘secular’ actually means ‘independent of or uninfluenced by religion”. It does not mean “embracing all religions” as is commonly misused. A secular state is supposed to act objectively.
We need not fear that ethics will not have an anchor in the absence of religion. It can exist and evolve by itself.