The Rambam in Moreh Nevuchim says "That those who have prepared themselves may still be prevented from being prophets, may be inferred from the history of Baruch, the son of Nerijah; for he followed Jeremiah, who prepared and instructed him; and yet he hoped in vain for prophecy;", which seems to imply that Baruch son of Nerijah was not a prophet however the Gemara on, Megillah 14b seems to imply that he was a prophet. How do you reconcile this?
This can perhaps be explained by what Rambam writes later in Guide for the Perplexed (2:45) where he explains that there are various levels of prophecy, some which make one an actual prophet and some which make one a prophet only in a loose sense. And furthermore the same person can at one time be a full prophet and at other times not be a full prophet. It is thus possible that Rambam means that Baruch was not a full prophet, but he was enough for the Talmud to call him a prophet, or that at a particular time Baruch did not qualify as a prophet but the Talmud refers to a different point in time.
AFTER having explained prophecy in accordance with reason and Scripture, I must now describe the different degrees of prophecy from these two points of view. Not all the degrees of prophecy which I will enumerate qualify a person for the office of a prophet. The first and the second degrees are only steps leading to prophecy, and a person possessing either of these two degrees does not belong to the class of prophets whose merits we have been discussing. When such a person is occasionally called prophet, the term is used in a wider sense, and is applied to him because he is almost a prophet. You must not be misled by the fact that according to the books of the Prophets, a certain prophet, after having been inspired with one kind of prophecy, is reported to have received prophecy in another form. For it is possible for a prophet to prophesy at one time in the form of one of the degrees which I am about to enumerate, and at another time in another form. In the same manner, as the prophet does not prophesy continuously, but is inspired at one time and not at another, so he may at one time prophesy in the form of a higher degree, and at another time in that of a lower degree; it may happen that the highest degree is reached by a prophet only once in his lifetime, and afterwards remains inaccessible to him, or that a prophet remains below the highest degree until he entirely loses the faculty: for ordinary prophets must cease to prophesy a shorter or longer period before their death. Comp. "And the word of the Lord ceased from Jeremiah" (Ezra i. 1); "And these are the last words of David" (2 Sam. xxiii. 1). From these instances it can be inferred that the same is the case with all prophets. After this introduction and explanation, I will begin to enumerate the degrees of prophecy to which I have referred above.