Michael Horton, in his book, Christless Christianity: The Alternative Gospel of the American Church makes the assertion that Pelagianism is the “default setting” of the human heart. I can practically see your eyes glossing over right now. Let me give you a little background.
Pelagius was a British Monk (c. 354-after 418) who thought that Augustine’s (354-430) position of original sin was extreme and unfair. Augustine taught that man is unable to do any good because man, by nature, is inherently depraved. Basically we were born with a predisposition to sin. One example of this doctrine in Scripture is seen in Ephesians.
And you were dead in the trespasses and sins in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience— among whom we all once lived in the passions of our flesh, carrying out the desires of the body and the mind, and were by nature children of wrath, like the rest of mankind, (Ephesians 2:1-3, ESV).
We also see in Romans 5 that, “just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned,” (Romans 5:12, ESV).
Pelagius believed that we do not inherit Adam’s sin by imputation of guilt or by nature. The only effect, essentially that Adam has, Pelagius would say, is the example that he set. So from his perspective all are born neutral with no predisposition to evil. His position was rejected later by three different church councils. Back to Horton…
Horton contends that semi-Pelagianism has found a home in American Christianity, (pg. 62).
In most cases, I suggest, it is semi-Pelagianism that dominates American Christianity, just as it did the medieval church. While Augustinianism affirms that God does all of the saving and Pelagianism crowns our moral achievement with the “grace” of acceptance, semi-Pelagianism says that salvation is a process that depends on the coworking of God and humans.
Horton contends that “where we land” on this issue is likely the most significant factor in how we approach our faith, how we live our faith out, and how we share that faith with the world around us.
Update: I thought that it might be helpful to link to a post that Michael Patton of Reclaiming the Mind Ministries wrote in defense of imputation he briefly discusses contemporary positions and the historical theology of original sin.