This passage here is a scary and challenging passage for people to understand. But in learning to discern it, there is wisdom. (My comments follow and the bold emphasis is mine here.)

I Kings 13:1-34

1 And behold, a man of God went from Judah to Bethel by the word of the Lord, and Jeroboam stood by the altar to burn incense.
2 Then he cried out against the altar by the word of the Lord, and said, "O altar, altar! Thus says the Lord: 'Behold, a child, Josiah by name, shall be born to the house of David; and on you he shall sacrifice the priests of the high places who burn incense on you, and men's bones shall be burned on you.'"
3 And he gave a sign the same day, saying, "This is the sign which the Lord has spoken: Surely the altar shall split apart, and the ashes on it shall be poured out."
4 So it came to pass when King Jeroboam heard the saying of the man of God, who cried out against the altar in Bethel, that he stretched out his hand from the altar, saying, "Arrest him!" Then his hand, which he stretched out toward him, withered, so that he could not pull it back to himself.
5 The altar also was split apart, and the ashes poured out from the altar, according to the sign which the man of God had given by the word of the Lord.
6 Then the king answered and said to the man of God, "Please entreat the favor of the Lord your God, and pray for me, that my hand may be restored to me." So the man of God entreated the Lord, and the king's hand was restored to him, and became as before.
7 Then the king said to the man of God, "Come home with me and refresh yourself, and I will give you a reward."
8 But the man of God said to the king, "If you were to give me half your house, I would not go in with you; nor would I eat bread nor drink water in this place.
9 "For so it was commanded me by the word of the Lord, saying, 'You shall not eat bread, nor drink water, nor return by the same way you came.'"

10 So he went another way and did not return by the way he came to Bethel.
11 Now an old prophet dwelt in Bethel, and his sons came and told him all the works that the man of God had done that day in Bethel; they also told their father the words which he had spoken to the king.

12 And their father said to them, "Which way did he go?" For his sons had seen which way the man of God went who came from Judah.

13 Then he said to his sons, "Saddle the donkey for me." So they saddled the donkey for him; and he rode on it,
14 and went after the man of God, and found him sitting under an oak. Then he said to him, "Are you the man of God who came from Judah?" And he said, "I am."
15 Then he said to him, "Come home with me and eat bread."

16 And he said, "I cannot return with you nor go in with you; neither can I eat bread nor drink water with you in this place.
17 "For I have been told by the word of the Lord, 'You shall not eat bread nor drink water there, nor return by going the way you came.'"
18 He said to him, "I too am a prophet as you are, and an angel spoke to me by the word of the Lord, saying, 'Bring him back with you to your house, that he may eat bread and drink water.'" (He was lying to him.)
19 So he went back with him, and ate bread in his house, and drank water.

20 Now it happened, as they sat at the table, that the word of the Lord came to the prophet who had brought him back;
21 and he cried out to the man of God who came from Judah, saying, "Thus says the Lord: 'Because you have disobeyed the word of the Lord, and have not kept the commandment which the Lord your God commanded you,
22 'but you came back, ate bread, and drank water in the place of which the Lord said to you, "Eat no bread and drink no water," your corpse shall not come to the tomb of your fathers.'"
23 So it was, after he had eaten bread and after he had drunk, that he saddled the donkey for him, the prophet whom he had brought back.

24 When he was gone, a lion met him on the road and killed him. And his corpse was thrown on the road, and the donkey stood by it. The lion also stood by the corpse.
25 And there, men passed by and saw the corpse thrown on the road, and the lion standing by the corpse. Then they went and told it in the city where the old prophet dwelt.

26 Now when the prophet who had brought him back from the way heard it, he said, "It is the man of God who was disobedient to the word of the Lord. Therefore the Lord has delivered him to the lion, which has torn him and killed him, according to the word of the Lord which He spoke to him."
27 And he spoke to his sons, saying, "Saddle the donkey for me." So they saddled it.
28 Then he went and found his corpse thrown on the road, and the donkey and the lion standing by the corpse. The lion had not eaten the corpse nor torn the donkey.

29 And the prophet took up the corpse of the man of God, laid it on the donkey, and brought it back. So the old prophet came to the city to mourn, and to bury him.
30 Then he laid the corpse in his own tomb; and they mourned over him, saying, "Alas, my brother!"
31 So it was, after he had buried him, that he spoke to his sons, saying, "When I am dead, then bury me in the tomb where the man of God is buried; lay my bones beside his bones.
32 "For the saying which he cried out by the word of the Lord against the altar in Bethel, and against all the shrines on the high places which are in the cities of Samaria, will surely come to pass."

33 After this event Jeroboam did not turn from his evil way, but again he made priests from every class of people for the high places; whoever wished, he consecrated him, and he became one of the priests of the high places.
34 And this thing was the sin of the house of Jeroboam, so as to exterminate and destroy it from the face of the earth. (NKJ)

This is a very sobering story, especially for all who are called to the ministry, especially in the area of the prophetic. I am not about to say that I am an expert on this, but I will share what I have learned and discerned over the years.

First of all, prophets are human! Second of all, God does speak!

Many cry out to be used greatly by God and many times God will honor that but there is a high price to pay for the greatness. Some just want their place in the sun, but some have spirits who bear witness to the Kingdom of God. To share in God's glory is to give it to Him alone. And it pays to know the difference.

The work of God can be a lonely work. And even as King David found out when Uzzah tried to steady the ark, there can be a high price for not doing it right. But we also must understand that God is determined to make His points about many things, and even at the expense of men's lives.

I cannot judge God for this, and neither can you. There will be some who try. But the reverence and fear of the Lord is a wise thing to have!

We are human - we are mortal in this life - and we must pass through a judgment. There must be a place where we sacrifice our will for Another's. It is in that place where we can love and choose and master our soul - which is our decision making process. And not every decision is an easy one and we do not always understand God's compassion, but He does. But we know it by the individual witness in our soul, that He sees clearly.

Because we can't see the wind or the ways of the Spirit, Jesus told us to look at the fruit and judge (or discern) by that. Even then at times we can be fooled, but God really does honor our heart with the knowledge and understanding that He has. Grace is something that He is in charge of, it cannot be presumed or manipulated by man.

Ambition in the Lord can be a good thing. It's wonderful to be motivated by God! This young prophet had a heart to be used by God. But as Scriptures also say, we need knowledge with our zeal and some takes a while to learn.

The young prophet heard the word of the Lord; he obeyed it and he delivered it to the king. Many do not think through what something like that means. They see it in a fantasy story book setting, but prophets who went before kings, especially on a regular basis had to be able to go through the protocol of having audience with the king. There are many wanna-be prophets who just shoot off words they believe they hear but these are not relationship words.

If you do not understand God's goals, you will think that He wants to use you prophetically to correct the world from your own understanding. Your spirit may bear witness to many things - especially if one has been the victim of abuses - but that does not always mean that person has "the word of the Lord" telling them to go and prophesy. Sometimes they do, and God will sometimes use these people in spite of themselves but not with the rewards they believe they will get!

Some go into the deception of believing that they are helping God out, that He needs them for that, because many have been taught that we are the "only" hands and feet that God has, therefore He can't do anything without us. Beware of deception! Yes, God will use us but not with an agenda that is not His, and Uzzah should be an example to us of this.

2 Samuel 6:5-7

5 Then David and all the house of Israel played music before the LORD on all kinds of instruments of fir wood, on harps, on stringed instruments, on tambourines, on sistrums, and on cymbals.
6 And when they came to Nachon's threshing floor, Uzzah put out his hand to the ark of God and took hold of it, for the oxen stumbled.
7 Then the anger of the LORD was aroused against Uzzah, and God struck him there for his error; and he died there by the ark of God. (NKJ)

Uzzah wanted to help God out, but failed to realize that their protocol for carrying the ark was not right. When David understood that later, then things prospered for him.

This young prophet was human like all the rest. There are many who say that prophets ~never~ miss it or they are not prophets, and there are times when it can be challenging to discern if someone is a true or a false prophet. Some start off good and end up bad like Balaam. He was given the words of the Lord, but he went into corruption. This young prophet also faced a similar test.

In these Bible examples, we can see that the word of the Lord does come to His prophets but how they handle and manage these words makes a difference. Old Testament prophets were used by God to bring His messages, but Hebrews 1:2 explains to us in these times now, after the appearance and resurrection of Jesus, that God now speaks to us by His Son. There are still prophets and apostles, as it says in Ephesians 4, along with evangelists, pastors and teachers, but there He also gives their job descriptions, and He speaks to them and to all His sheep by His Son.

As we mature, we are called to minister to others, through the gifts the Lord has bestowed to us. Some look for status but miss the goal and plan of the Lord - which is for people to have personal relationship with Him - and it becomes evident later of their corruption. There are enemies of the Lord who look for these weaknesses in others because they want to destroy the work of the Lord. God is Love.

The enemy often understands God's plan better than some men! Someone who is tooting their own horn and knowledge is not as dangerous as someone who works the spirit of division and deception. This old prophet had the gift, but also a serious character flaw. He was a deceiver.

Now thank God, He can save deceivers like He did Jacob. But they will go through a wilderness. But we must also understand that some become fully corrupt.

Jesus refers to this in Revelation 2:13-14

13 "I know your works, and where you dwell, where Satan's throne is. And you hold fast to My name, and did not deny My faith even in the days in which Antipas was My faithful martyr, who was killed among you, where Satan dwells.
14 "But I have a few things against you, because you have there those who hold the doctrine of Balaam, who taught Balak to put a stumbling block before the children of Israel, to eat things sacrificed to idols, and to commit sexual immorality. (NKJ)

Some may believe in God but hold wrong doctrines in ignorance. Some though can be deceivers and work against the plan of God. Either way, they will face a judgment when they interfere. You must know God by His Spirit - they that really worship Him do worship Him in Spirit and in Truth. We can emotionally appeal for grace and God will often honor that, but He does see the heart that is for Him or is not.

I'll say it again. God is after relationship, not status. Some can be very manipulative and deceiving. I have seen people trying to force unity over integrity and call it God. God is not going for it. God will honor the structure to the point it serves His work. It doesn't meant it is always right.

We may try to be legal experts but you will not out perform the shrewdness of God. He is the Ultimate Judge and He will determine for Love with integrity. He sees the heart and the end results of those deeds. Many are in ministry for status and not for Jesus. Have you noticed how few ministers today talk about Jesus and how many use the Word to talk about the individual's personal gain?

We need pep talks and we need good people who will show us how to prosper, but if you don't see the personality of Jesus, watch out! Is He lifted up or are they "doing Him favors"? Does He need them or do they need Him? Is He God or not?

Jude 1:10-13

10 But these speak evil of whatever they do not know; and whatever they know naturally, like brute beasts, in these things they corrupt themselves.
11 Woe to them! For they have gone in the way of Cain, have run greedily in the error of Balaam for profit, and perished in the rebellion of Korah.
12 These are spots in your love feasts, while they feast with you without fear, serving only themselves. They are clouds without water, carried about by the winds; late autumn trees without fruit, twice dead, pulled up by the roots;
13 raging waves of the sea, foaming up their own shame; wandering stars for whom is reserved the blackness of darkness forever. (NKJ)

2 Peter 2:15-16

15 They have forsaken the right way and gone astray, following the way of Balaam the son of Beor, who loved the wages of unrighteousness;
16 but he was rebuked for his iniquity: a dumb donkey speaking with a man's voice restrained the madness of the prophet. (NKJ)

The old prophet was nosey. He was competitive. He wanted to see if this young upstart had something he didn't. And he was not above lying to find out. The Lord allowed the test. It can seem like a high price to pay.

The young prophet wanted company, but God knew the old prophet was there. The old prophet invited him to come in and feast - doesn't the human soul want that? Food and fellowship are not bad. We might even learn about an angel! But the old man was lying and the young prophet needed to discern it.

Because he didn't, it cost him his life. Why was God so severe? This young prophet did not just speak to his friends, he spoke to the king. His words, backed by God with signs and wonders following, affected the whole nation. Word traveled. This prophet must be believed! But if the prophet could fail, then God could not use him. God will defend His plans.

Probably at their luncheon, the old prophet said, "I don't know what came over me! Those words just came out!" The young prophet went on his way, only to be met by the Lion of Judah. Compassion was evidenced. He died, but he died as deceived and not as a deceiver. His body remained intact and the lion did not hurt that work or that of the donkey, which was the vehicle (or ministry) that carried the word of the Lord.

The old prophet invited fellowship and the young prophet wanted to receive it, but it was not allowed at that place at that time.

To be used by God is not something that we invent. We don't plot and plan performances "for God." We can be motivated by our calling to do things and often God will honor that but if we are just looking to be seen, our "performance" will be spoiled. We entreat God by His mercies, we don't tell Him what to do.

If we are just looking to have a ministry because we like that idea, we need to be careful that we are not crossing the purposes of God. Even the Apostle Paul was careful not to build on another man's foundation, but true works of the Lord will be compatible! When bickering and fighting and strife occur, there is a problem somewhere. You must seek your solutions in God.