Who are Right -- Protestants or Catholics?

Who are Right -- Protestants or Catholics?: "Who are right, Catholics or Protestants? Is there any difference between their beliefs besides that Protestants don't consider the Pope the earthly leader of all Christians?'
There are fundamental differences between Roman Catholicism and all Protestant and Messianic Jewish denominations.

Note: This is a very general overview. For details see the Catholic Catechism Compared to the Bible--quote-for-quote.
PROTESTANT / MESSIANICCATHOLIC (official text)
The Old and New Testaments are the only sources of Christian doctrine.
(Messianic Judaism refers to these by their Hebrew names, Tanakh and B'rit Chadasha ['New Covenant'])Sources of doctrine include:

Certain papal declarations
Bishops in conjunction with the pope
Old Testament
New Testament
Apocrypha (some additions to the Bible)
Catholic Church Tradition
Catholic interpretation of the Bible

We are justified (saved) by faith alone, not by good works. Good works will result in greater rewards in the afterlife but have no effect on getting saved. This 'faith' means relying on Jesus' sacrifice as full atonement for our sins and trusting in God enough to try to live as he said to live. It is not mere intellectual belief in a set of facts.When a person gets baptized his 'original sin' is forgiven and God gives him some grace. This grace enables him to do good works. God appreciates the good works and rewards them with more grace. Because the Christian has more grace, he can now do even better works. This pleases God even more, so He gives even more grace, etc.
Purgatory is totally unscriptural. Christ's sacrifice on the Cross was th"