A prophet also must not contradict the bible. It is very difficult for many to stick to this one.
The purpose of a prophet of and to Jesus Christ is to call the people into a deeper relationship with Jesus and through Him with God. And if that relationship is missing or refused, to point out the consequences of disobedience.
In truth, this should be the purpose of every minister of the gospel of Jesus Christ.
But we want it judge others and see if they are true. The truth is in us, if we will hear. The Holy Spirit will confirm every word thatcalls for a growing relationship with Jesus. The religious spirit will argue against these same words.
A prophet cannot be concerned with how the word is received, or whether it is according to another's interpretation of scripture. A religious person will see scripture in a very different way from a spiritual person. So a prophet must be true to speak as he hears.
Truly, the judgment for apostles and prophets is stricter, much more severe.