Called to be prophets?

So the Amos essay is finished, but has left me with a question. The second part of the essay question was about prophesy in the contemporary church. The message of Amos, and other Hebrew prophets, is very similar to the message today in liberation theology. It is also like the message Jesus brought and showed through the example of his life. So if we are followers of Christ, should we also not be speaking out the message of liberation theology - that oppression, injustice and hypocrasy are unacceptable, that all people should be treated equally, as God treats us all? And if we are, then are we, like Amos, speaking the word of the Lord God, like Amos? So are we not then all called to be prophets? And if we are called, are we answering that call?