Not always true. If something could be defined as a lie, especially about something they are advising someone to do, they would be a false prophet. If they are lying about something to protect themselves from danger that is something else. If they are actually saying something that is not a lie but would require someone to investigate further what they meant then that is another situation also. If the lied because they saw the damage that would happen due to inaction then that is another, YET they always pay a price for that.
Besides, the concept of a prophet is different for Christians than it is for Torath Mosheh Jews.
I understand the differences in today's NT prophets vs TaNaKh prophets.
Hmmm... let me see if I can find it:
11 Now there dwelt an old prophet in Bethel; and his sons came and told him all the works that the man of God had done that day in Bethel: the words which he had spoken unto the king, them they told also to their father.
12 And their father said unto them, What way went he? For his sons had seen what way the man of God went, which came from Judah.
13 And he said unto his sons, Saddle me the ***. So they saddled him the ***: and he rode thereon,
14 And went after the man of God, and found him sitting under an oak: and he said unto him, Art thou the man of God that camest from Judah? And he said, I am.
15 Then he said unto him, Come home with me, and eat bread.
16 And he said, I may not return with thee, nor go in with thee: neither will I eat bread nor drink water with thee in this place:
17 For it was said to me by the word of the Lord, Thou shalt eat no bread nor drink water there, nor turn again to go by the way that thou camest.
18 He said unto him, I am a prophet also as thou art; and an angel spake unto me by the word of the Lord, saying, Bring him back with thee into thine house, that he may eat bread and drink water. But he lied unto him.
19 So he went back with him, and did eat bread in his house, and drank water.
20 And it came to pass, as they sat at the table, that the word of the Lord came unto the prophet that brought him back:
21 And he cried unto the man of God that came from Judah, saying, Thus saith the Lord, Forasmuch as thou hast disobeyed the mouth of the Lord, and hast not kept the commandment which the Lord thy God commanded thee,
Let's see....
Both prophets? yes
One lied? true
Any false prophets? no
Did one prophet's lie cause the other to stray? yep
Did the strayed prophet suffer the consequences? sure thing.
did the other prophet stop being a prophet... apparently not, he prophesied the death of the other and it happened.