For Christian Catholics there is a formation of conscience that is a lifelong task.  This development of a moral sense of right and wrong starts in the family with your parents.  This conscience formation continues as you have contacts with Church leaders and teachers.  Finally, the role of peers leads to a personal synthesis.  What should I do in this particular case?  I will act based on what my conscience has decided.  If it is poorly formed, I must still follow it.  If I differ from the teachings of the Church, I must try to figure out why I differ from the group.  We always need an informed conscience.