Voltaire never lived to see the French Terror, where the Jacobins killed more people in one year than the Inquisition did in several hundred. The war in the Vendee was ever bit as savage any any of the Wars in relgion in France in the 16th Century. You are right. Every civilization is shaped by a "religion" if we include in that ideologies which substitute for religion. The problem is that "reason" tends to dissolve into the sovereignty of the will and blood lust. Liberalism's acceptance of abortion on demand is nonetheless bloodthirsty even if the killing is done by surgical instruments rather than swords.
Well, let's split the difference: when we [or the Israelis, which is more likely] nuke iran, on their ledger it would be counted as religion, and on ours - as secular. Yes, let's split the difference.