The consequences of Adam's sin for humanity
The doctrine of original sin, closely connected with that of redemption by Christ, provides lucid discernment of man's situation and activity in the world. By our first parents' sin, the devil has acquired a certain domination over man, even though man remains free. Original sin entails "captivity under the power of him who thenceforth had the power of death, that is, the devil". Ignorance of the fact that man has a wounded nature inclined to evil gives rise to serious errors in the areas of education, politics, social action and morals.
Source: Catechism of the Catholic Church (Vatican.va)