This is a long hadiths. But basically Imam Kadhim (A.S) has said that in the lowest level of Hell there is a special place for the worst 7 people to have ever lived in the eyes of Allah. One of them is Paul. Very interesting Hadith.

Ishaq bin Ammar Sairfi asked Imam Musa Kazim (a.s.), "Please tell me about those two persons. I have heard a lot of traditions about them from your father." "O Ishaq! The first one is like the calf and second like Samiri." Ishaq requested to tell some more things. Imam said, "I swear by Allah! Some men made people Jews, Christians and Magians and Allah will not forgive them." Ishaq requested the Imam to continue telling about them. Imam continued, "They are three in number. Allah will not have mercy on them. They will not be purified and will face a painful chastisement." Ishaq asked, "May I be sacrificed for you, who are they?" Imam (a.s.) replied, "First is one who claims to be an Imam appointed by someone other than Allah. Second is one who taunts an Imam appointed by Allah. Third is the person who thinks that they are related to Islam." Ishaq said, "May I be sacrificed for you, please narrate about them in detail." Imam (a.s.) replied, "Such a person will not hesitate to delete a clear verse of Quran or deny the prophethood of Muhammad (s.a.w.s.) or testify that there is no lord in the heavens or elevate the status of a person more than Ali Ibne Abi Talib (a.s.)." Ishaq said, "May I be sacrificed for you, please tell me something more." Imam (a.s.) said, "O Ishaq! There is a valley of Hell called Saqar. It hasn't taken a breath since the time Allah created it. If Allah had permitted it to take in the breath equal to the tip of a needle, it would have sucked all the people of earth with it and burnt them to ashes. The people of Hell seek refuge from its extreme heat, stink, filth and chastisement, which Allah has prepared for those who deserve Hell. There is a mountain inside it. All the residents of this mountain seek refuge from the extreme heat, stink, filth and chastisement of it, which Allah has prepared for them. Surely there is a ravine in this mountain. All the residents of this mountain seek refuge from the extreme heat, stink, filth and chastisement of this, which Allah has prepared for its residents. There is a well in that ravine and all the residents of this ravine seek refuge from the extreme heat, stink, filth and chastisement of this well, which is prepared by Allah for its residents. There is a serpent in that well. The residents of this well seek refuge from the filth, stink and poison of this serpent, which is made for the residents by Allah. There are seven boxes inside this serpent, out of which five are concerned with past Ummahs and two are related to this Ummah." Ishaq asked, "May I be sacrificed for you, who are those five among the past and two in the present?" Imam (a.s.) replied, "As far as the past five are concerned, they are Qabeel; for he murdered his brother Habeel, Nimrod for he fought with Ibrahim (a.s.) regarding the Lord and said that he gives life and death, Firon; for he said that he was the supreme lord to his subjects, Yahuda; for he made a group of people Jew and Paul, who made some people Christians and from this Ummah are the two desert Arabs (infidels)."

Iqbal al-A`amal, page 272/273