YOUR QUESTION (No. 56)
Who decided what books should be in the Bible and the ones that should not?
Rome, the Pope, Eastern prelates and such as Augustine had a hand in it. How the canon came to include its documents is a fascinating story that dragged out for nearly four centuries before it was finally settled. Or, we might say for 1500 years, because, until the reformers, it included the apocryphal books -- and the Catholics did not finally confirm their version, in reaction to the Protestants, until 1546!. You can read the details of this history at this site -- http://www.bible-researcher.com/canon1.html.
But Jesus our Lord decided on the canon for his disciples:
John.14I believe him because he makes sense of my life in the world, and of the world as it is with it bittersweet mix of love and hate, good and evil, war and peace. From him I have learned that it cannot be otherwise and we be responsible for our actions and choices.