For the most part, we don't know much about most of the prophets outside of Jonah and Daniel. We're familiar with parts of Isaiah and Jeremiah, but if we're reading the Bible the prophets (minor and major) tend to get skipped over. Prophets are tough to read, that's granted. To understand them, we have to understand the historical situation they were speaking to (contrary to popular belief, prophets generally spoke to their contemporary situation, not to future events).
The prophets are also hard to read because we find that God sometimes asks people to do crazy things. Things like marrying an unfaithful prostitute as an object lesson for the nation. Or walking around naked for three years. Or lying on your side in the middle of the city for over a year. I mean, if this is what following God could lead to, don't sign me up!
Yet, if you want to hear the voice of God, listen to the prophets. Most of the time they are speaking the words God has told them to speak. And some of the time it is tough words--usually of impending doom. But only if the people (or nation) don't change their ways. Only if they continue ignoring God. Only if they keep living in sin.
But they also often end with hope. With a promise that God will forgive them. That even after exile, God will bring them back home. That God will work through their consequences to make His love known. That God will bring hope into hopelessness.
And for us, the words of the prophets remind us to not turn from God. Not because bad things will happen to us, but because life is so much fuller when we're living in obedience and in the center of His love. And the words are also reminders for us to speak hope into hopelessness, life into death.