When Lukretius (his full name was Titus Lucretius Carus) wrote his book "On the nature of things" (in the first half of the last century B.C.), he already blamed religion for obstructing human rationality with superstition, believing dogma rather than believing observations and misguiding our entire life towards fear of death rather than joyful anticipation of the real world. Making religion responsible for so much evil in the world (Tantum religio potuit suadere malorum), he was mainly referring to the ancient roman faith, which was notorious for not only prefering superstition against rationality, but also promoted sacrificing animals and even human to please their gods.
Would Lukretius have ever forseen, that centuries later masses of mentally blind-folded people followed the papal "call of duty" to raid the non-christians during three crusades. Would he believe, that again and again warmongers could rely on the churches to praise the million-fold killings on the battle-fields. Would he believe that at the beginning of the 21st century, despite free education and an era of enlightment, young people from civilized societies follow islamic preachers who order them to kill and destroy everything that is not in accordance to some anachronistic holy writings.