What is a prophet?

To understand the biblical meaning of “prophet,” one has to distinguish the biblical sense of prophecy from the popular notion that a prophet predicts the future. A person who claims to foretell future events is more properly described as an “oracle”.
By Yemti Harry Ndienla

The word “prophet” comes from a Greek word that means “one who speaks on behalf of another.” In the Judaeo-Christian tradition, the “another” is God. Thus, prophets are those who speak on behalf of God. They have the gift of seeing things from God's perspective and their primary focus is on the present. Insofar as they talk about the consequences of the present course of action, they also look to the future.

It would be best to say: “Prophets forewarn; they don't foretell.”
“On that day the deaf shall hear the words of a book; and out of gloom and darkness, the eyes of the blind shall see. The lowly will ever find joy in the Lord, and the poor rejoice in the Holy One of Israel.(Is 29:17-24)

And “the lowly will ever find joy in the Lord..” Joy.
Great tidings of joy. Joy to the world.
The word “joy” can be used in different ways. Roget's Thesaurus says it can mean happiness, gladness, delight, delegation, cheer, glee, gaity, intoxication – you get the rest.

When Jesus says to the disciples at the Last Supper table: “I have told you this so that joy might be in you and your joy would be complete” - he uses the Greek word “chara”. Taken from the word “charis” which means grace.

That's getting to the heart of what biblical joy really mean.
Simply put, “grace” means God leaning towards me, bending over me, inclining towards me kindly, favorably.”

That's what God is and that's who God is for us. There is never a moment when God isn't moving toward me that way. No matter what the situation, God is leaning toward me kindly, favorably. And it's God's initiative. It's got nothing to do with whether I deserve it. Now that's a tiding of great joy.