In Islam sin is law-breaking. It does not corrupt the hearts and minds of wrong-doers. Adam's sin did not damage the world in any way. The punishment for the wrong-doing of Adam and his wife was to be sentenced to life on earth. The descendants of Adam are all put to the test of obedience, though according to most Muslims, no-one is considered to be guilty before they are born.
Man is created weak and makes faults and mistakes.
Allah has given a blueprint for every facet of life, including criminal, social, civil and religious laws. Deviaton from this pattern is sin resulting in failure in society, relationships, commerce and culture. Eternal sins are only applicable to unbelievers or apostates of Islam. Normally Muslims are protected by Allah from the above sins, though this protection is not afforded to non-Muslims. There are, however, punishments for each and every sin.