It guaranteed individual religious and political rights.
The Magna Carta was important for many reasons. It placed limits upon the absolute power of the King and made him subject to the law. It confirmed the liberties of the Church and of all towns and cities. It attempted to regulate the conduct of all local officials such constables, bailiffs and sheriffs and ensure that they observed the law and knew the law. It provided for uniform measures of cloth, ale and wine. There were other things as well. There were in fact 63 clauses. The majority of the 63 clauses deal with feudal rights and customs, plus the administration of justice. One most famous clause said that no free man could be imprisoned, outlawed or exiled except by the lawful judgment of his peers or by the law of the land, and that justice could not be sold, delayed or denied. One is not surprised that the regulation of the justice system and feudal rights dominate the Magna Carta content. It was (more than anything else) King John's abuse of the justice system, and his exploitation of his feudal rights, which had given rise to the barons' rebellion.