Firstly:
The authentic religious texts indicate that Paradise has degrees (darajah), and that there are one hundred degrees, and that the highest degree is that of the Prophet (blessings and peace of Allah be upon him). These degrees are also called stations (manzilah).
Allah, may He be Exalted, says:
{Look how We have favored [in provision] some of them over others. But the Hereafter is greater in degrees [of difference] and greater in distinction} [Al-Isra’ 17:21]
{And for all are degrees from what they have done} [Al-An`am 6:132].
Al-Bukhari (2790) narrated that Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “In Paradise there are one hundred degrees that Allah has prepared for those who strive in the cause of Allah; the distance between each two degrees is like the distance between heaven and earth. So if you ask of Allah, then ask Him for al-Firdaws, for it is the middle of Paradise and the highest part of Paradise. I think that above it is the Throne of the Most Merciful, and from it spring the rivers of Paradise.”
The Prophet (blessings and peace of Allah be upon him) gave an explanation of his degrees and station, in the report narrated by Muslim (384) from `Abdullah ibn `Amr ibn al-`As (may Allah be pleased with him), who said that he heard the Prophet (blessings and peace of Allah be upon him) say: “When you hear the mu’adhdhin, say what he says, then send blessings upon me, for whoever sends blessings upon me, Allah will send blessings upon him tenfold. Then ask Allah to grant me al-wasilah, for it is a station in Paradise which only one of the slaves of Allah will attain, and I hope that I will be the one. Whoever asks for al-wasilah for me, intercession for him will be permissible.”
At-Tirmidhi (3612) narrated that Abu Hurayrah said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Ask Allah to grant me al-wasilah.” They said: O Messenger of Allah, what is al-wasilah? He said: “The highest degree in Paradise which no one will attain except one man, and I hope that I will be the one.” Classed as authentic by al-Albani in Sahih at-Tirmidhi.
Ahmad (11783) narrated that Abu Sa`id al-Khudri said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Al-wasilah is a degree with Allah above which there is no other, so ask Allah to grant me al-wasilah.”
Ibn al-Qayyim (may Allah have mercy on him) said: The degree of the Prophet (blessings and peace of Allah be upon him) is called al-wasilah because it is the closest of the degrees to the Throne of the Most Gracious, and it is the closest of the degrees to Allah. The root meaning of the word al-wasilah is to draw close to someone, and it refers to drawing close to Allah.
Hence it is the best, the noblest and the most light-filled… As the Messenger of Allah (blessings and peace of Allah be upon him) was the greatest of humankind in servitude to his Lord, and was the most knowledgeable of them about Him, and the one who feared Him the most and loved Him the most, his station is the closest of stations to Allah and is the highest degree in Paradise. The Prophet (blessings and peace of Allah be upon him) instructed his ummah to ask Allah to grant it to him, so that they might draw closer to Allah by virtue of this supplication and increase in faith.
This proves that the station (manzilah) is the same thing as the degree (darajah), because the Prophet (blessings and peace of Allah be upon him) called al-wasilah a station, and he also called it a degree.
This is also indicated by the report narrated by Bukhari (3256) and Muslim (2831) from Abu Sa`id al-Khudri (may Allah be pleased with him), from the Prophet (blessings and peace of Allah be upon him) who said: “The people of Paradise will see the people of the lofty dwellings in Paradise above them as you see a brilliant star far away on the horizon in the east or the west, because of the difference in status between them.” They said: O Messenger of Allah, is that the station of the Prophets that no one else will attain? He said: “No, by the One in Whose hand is my soul. They are men who believed in Allah and believed in the Messengers.”
And Muslim (189) narrated that al-Mughirah ibn Shu`bah said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Musa (peace be upon him) asked his Lord: ‘Who will be the lowest of the people of Paradise in station?’ He said: ‘He will be a man who will come after the people of Paradise have been admitted to Paradise and it will be said to him: ‘Enter Paradise.’ He will say: ‘O Lord, how, when the people have taken their places and have received that with which Allah has honoured them?’ It will be said to him: ‘Would it please you if you had the like of what one of the kings of the world had?’ He will say: ‘I would be pleased, O Lord.’ He will say, ‘You will have that, and as much again, and as much again, and as much again, and as much again.’ The fifth time, he will say, ‘I am pleased, O Lord.’ He will say: ‘You will have that and ten times as much, and you will have what your heart desires and what will delight your eyes.’ He will say: ‘I am pleased, O Lord.’”
The people of Paradise will vary in their stations (manzilahs), which are the degrees (darajahs), as is known from the hadiths quoted above.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: Paradise is degrees which vary greatly. The pious, believing close friends of Allah will be in those degrees at a level commensurate with their level of faith and piety.
End quote from Majmu` al-Fatawa, 11/188.
As-Suyuti (may Allah have mercy on him) said, commenting on the hadith of Abu Sa`id al-Khudri, that the Messenger of Allah (blessings and peace of Allah be upon him) said: O Abu Sa`id, whoever is content with Allah as his Lord, with Islam as his religion and with Muhammad as his Prophet, Paradise will be due to him.” Abu Sa`id was amazed and said: Tell me that again, O Messenger of Allah. So he did that, then he said: “And there is something else by means of which Allah will raise a person one hundred degrees in Paradise, and the distance between each two degrees is like the distance between heaven and earth.” [Abu Sa`id] said: What is it, O Messenger of Allah? He said: “Jihad in Allah’s cause, jihad in Allah’s cause.”
Al-Qadi said: It may be that this is to be understood in accordance with the apparent meaning, and that the degrees (darajahs) here are the stations (manzilahs), some of which are above others, as appears to be what is meant. This is a description of the stations of Paradise, as it was narrated that the occupants of the lofty dwellings of Paradise will see one another as they see a brilliant star. Or it may be that what is meant is a high level in a metaphorical sense, referring to abundant blessings and divine generosity, and that that will vary greatly, or that the difference in virtue between them is as great as the distance between heaven and earth. Al-Qadi said: The first meaning is more likely.
Al-Qurtubi said: The degree is high status, and what is meant is the lofty dwellings of Paradise and the various levels of those dwellings, the loftiest of which is al-Firdaws.
End quote from Ad-Dibaj `ala Sahih Muslim ibn al-Hajjaj, 4/475.
Al-Qastallani (may Allah have mercy on him) differentiated between the station (manzilah) and the degree (darajah), by stating that whatever is given as a reward for righteous deeds is called manzilah, and whatever is given by Allah’s grace or because of some intercession is called darajah. See: At-Tanwir Sharh al-Jami` as-Saghir, 7/275.
The religious texts do not support this differentiation, and we could not find the basis for his argument.
Secondly:
It is not impossible that most ordinary believers will attain the highest levels of Paradise, as mentioned above in the hadith of the stations of the Prophets and in the hadith “When you ask of Allah, ask Him for al-Firdaws.” That is the grace and bounty of Allah that He bestows upon whomever He wills.
And Allah knows best.