Pelagianism is a theory named after Pelagius. It is the belief that people are not born with original sin and that mortal will is still capable of choosing good or evil without Divine aid. For this reason, Adam's sin was there to set a bad example for those that came after him; other than that it had no consequences. Jesus was there to set a good example (much like Adam's bad example) but also to pay the price for our sins. Pelagius believed that because people "choose" to sin, they are like criminals who need to be pardoned, "not" victims of an inherited sinful nature.