It's not easy to be God's spokesperson - especially the prophetic kind. Jeremiah is totally committed to be God's messenger: "When your words came, I ate them; they were my joy and my heart's delight, for I bear your name, O Lord God Almighty" (15:16). God's message totally consumes him and he was sold out to proclaim it. But unlike the evangelist who brings good news, the prophets are seldom welcomed even their own home town because they are always preaching against the sins of the people. As humans, we naturally love people who preach good news; but we resent those who point out our sins and make us feel guilty and condemned.
In the OT, the prophetic movement arose during the period of the monarchy because God's people were continually straying from God and consorting with idols and Baal worship. If there has been no backsliding into sins, there would have been very little need for prophets. So, Saul was afraid of Samuel because Samuel was always confronting him over his failures to comply with God's orders. So, also David has his close encounter with the prophet Nathan when he committed adultery with Bathsheba. In the same ways, all the kings of Israel and and many of the kings of Judah that did what was evil in the sight of the Lord and the Lord raised up prophets to confront them about their sins. Prophets and evil people cannot co-exist: either one or the other has to go.
When a pre-believer rejects the evangelist's message, his or her spiritual status remains unchanged, which is a state of condemnation and judgment: "Whoever believes in him is not condemned, but whoever does not believe stands condemned already because he has not believed in the name of God's one and only Son" (John 3:18). But when a believer rejects the prophet's call to return to the Lord, his or her spiritual status as son or daughter does not change but his or her experience of God's love degenerates from divine pleasure to divine pain: "Then the Lord said to me: "Even if Moses and Samuel were to stand before me, my heart would not go out to this people. Send them away from my presence! Let them go! And if they ask you, 'Where shall we go?' tell them, 'This is what the Lord says: Those destined for death, to death; those for the sword, to the sword; those for starvation, to starvation; those for captivity, to captivity.'"
Yes, even in the New Testament, God disciplines those He loves because He is our Father: "Endure hardship as discipline; God is treating you as sons. For what son is not disciplined by his father? If you are not disciplined (and everyone undergoes discipline), then you are illegitimate children and not true sons" (Heb 12:7-8). Those earthly fathers who do not discipline their children do not really love them.
When obedient people hear a rebuke from the Lord, they repent, but when a rebellious people hear a rebuke from the Lord, they resent. That is why Jeremiah has an unenviable task: he was proclaiming God's prophet word to a rebellious people. Their response was almost predictable: When the same is done to rebellious people, they persecute and kill the messengers. Jeremiah was experiencing the negative reactions of a very rebellious people: they were persecuting and plotting to kill him. But nevertheless, God's word to is this: "they will fight against you but will not overcome you, for I am with you to rescue and save you, declares the Lord" (15:20).
God will back up His prophets. But we're called to speak the truth, to be God-pleasers, not man-pleasers.
Father, deliver us from the fear and displeasure of men so that we may speak the truth even if it's unpleasant to hear. Amen.