Many Christians have been indoctrinated with a misconceived unBiblical theology promoting a non-application oriented mental assent type of faith and even reckoning any personal efforts to repent and do good as legalistically disqualifying one from salvation! Furthermore what is commanded in this passage contradicts some Christian's concept of the Total Depravity of man. Such Christians will never preach what Isaiah has preached here, nor what the apostle Peter preached in Acts 2:40 which says that with many other words he testified, and exhorted them, saying, "Save yourselves from this crooked generation!" There is a correlation between a willing repentance, an obedient behavior and the forgiveness of sins. Many in the Evangelical community today are decieved on this point, but Paul writes,
"Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God." 1Cor 6:9,10