All praise to Allah Subhanahu wa Taala and blessings on Prophet Muhammad peace be upon him His family and companions
Hasnaa’ bint Mu’aawiyyah from Bani Suraym said: my paternal uncle told me: I said, O Messenger of Allaah, who will be in Paradise? He said: Prophets will be in Paradise, martyrs will be in Paradise, infants will be in Paradise and baby girls who were buried alive will be in Paradise. Narrated by Imaam Ahmad
Yeah Prophets are the people of Paradise without any doubts in Islam.It is not unjust at all as what Allah Swt knows we are unaware of it,no one on the whole universe is able to reach upto his knowledge and wisdom.It is one of the obligatory belief in Islam that Prophets are trustworthy and preserved from sin.
Imam Al-Ghazali writes in his work Rawda-tut-talibin:
It is established by consensus (ijma) that the Messenger of Allah is free of committing grave sins, venial sins, and makruhs. It is also established by consensus that he is free of forgetfulness, negligence, and making a mistake and erring in the messages he conveys.
If there have been some occurences seem to be errors not suitable to their diginity was to teach and explain the religion to their followers.
A Scholar has mentioned that because the Messenger of Allah (Allah bless him and give him peace) was continually rising in degrees to higher stations, the previous, lower station in relation to the higher station was akin to a sin with respect to him. And others have said that his seeking forgiveness was simply to establish a sunna for his community as he (Allah bless him and give him peace) was free and exalted from sin. [Biqa`i, Nazm al-Durar fi Tanasub al-Ayat wa al-Suwar; al-Suyuti/al-Mahlli, Tafsir al-Jalalayn]
Now Suppose if some one doesnt think about Prophets (the Chosen ones)
as people of Paradise Nauzubilaah min Zalik what could be the
--To think them that they could do any sins by disobeying Allah Swt which could lead them to hell Nauzubilaah.Which is Negating this verse of Quran
"And We did not send any messenger except to be obeyed by permission
of Allah ."(4:64)
--They could perform any sin so they are not perfect enough to send messages from Allah Swt to their followers.Then followers could have
doubtful in their teachings and orders Nauzubillah.Negating this verse of Quran
"Nor does he speak out of his own desire"(53:3)"O you who have
believed, obey Allah and obey the Messenger and do not invalidate your
deeds.(By disobeying him)"(47:33),He who obeys the Messenger has
--So followers would be doing sins as well by following prophets who are sinners Nauzubillah.Allah SWt says "So be patient for the decision
of your Lord and do not obey from among them a sinner or ungrateful
--So followers have no perfect guidance at all to seek the path to Allah Swt Nauzubilaah negating "And those who disbelieved say, "Why has a sign not
been sent down to him from his Lord?" You are only a warner, and for
every people is a guide."(13:7)It is He who has sent His Messenger
with guidance and the religion of truth to manifest it over all
--So there would be no hope for salvation for followers if Prophets are going to hell,whom should people follow then if they have no
perfect role models Nauzubilaah ,negating "And indeed, you are of a great moral
character. "(68:4) "Say, [O Muhammad], "If you should love Allah, then
follow me, [so] Allah will love you and forgive you your sins. And
Allah is Forgiving and Merciful."(3:31)
There is a beautiful wisdom of Allah swt that he elected prophets as chosen ones as people of pardise ,It is offcourse for you,me and other followers so that we could become people of Paradise too In Sha Allah by following their teachings and path.
One Scholars has mentioned in regard of some question" It is advisable not to approach the status of Prophethood with inquiries except with the highest good manners. Prophets are the elect of the Creator and like or above the angels in rank. We should take care, also, to focus on what is vital to our salvation and relinquish pursuits that are not only irrelevant but actually damaging to faith and works."
Allah Swt is the "Just" Creator, Who never commits any injustice against His creation.
Allah Swt and His Messenger knows best.