The Rambam and Kuzari both have an opinion of what the it takes to be a Navi .... let's see what they have to say!
The Rambam says that for a Navi to receive prophesy there must be a partnership between him and Hashem! He must be a pious man who is wise, righteous, and learned who has prepared himself through constantly perfecting himself. But that's not enough! Even if the person is perfect, he may never be a Navi unless Hashem chooses to let Divine Spirit rest upon him.
The Rambam also says that even a non-Jew could be a Navi if he reaches this state and Hashem chooses him!
The Kuzari agrees with everything Rambam says, but he adds that every Navi can only have nevua if they are in Eretz Yisroel of if it is for Eretz Yisroel's sake!
So it seems that it takes a lot of work and a lot of faith to become a Navi!