What are the primary doctrinal differences between Roman Catholicism, Lutheranism, and Calvinism?

Lutheranism has several sub-branches that are led by the actual bishops and priests who have a religious authority, in the tradition of the Roman Catholic Church. Calvinism, on the other hand, being a purer form of Protestantism, completely rejects the authority of the interpreters of God’s teachings, starting with the Pope’s.

Calvinism teaches the absolute sovereignty of God. The concept of sovereignty is of utmost importance. God accomplishes all things he has chosen to accomplish and never fails. This leaves very little for a man, since God knows better. For Lutherans, on the other hand, a concept of Sovereignty is not very important, similar to other abstract theological concepts. Martin Luther and his followers saw the primal point of theology in Jesus Christ being given to humanity in the form of Words and the Sacraments.

Roman Catholics teach that the Roman Catholic Church is the only true church, and that the pope is the supreme authority over the church, having received his authority by direct apostolic succession from Peter. Calvinists teach that there is no such thing as apostolic succession which hands such authority down from person to person, and that there is no single visible entity or church which may be indentified as "the true church."

Explanation:

1. Based on evidences most of  the descriptions he gave in his documents were inaccurate, there were discrepancies  in these;for example of the  rulers  accounts he gave before and after life time, and the geographical details he gave.

2.It was not possible for him to embark such a long  journey(73,000miles) at that time he quoted in his narration,due to the circumstances of the  events then; the means of transportation was  not fast then

3.Because many expedition had occurred  before his time,there was believe that his narration was based on compilation of contemporary travel reports (Plagiarism)of the period. E.g most of the pilgrimage  accounts he gave were word-for-word  of Ahmad  Ibn Jubayl.