[16].Surah An-Nahl [The Bees] : Ayat 88

Ayat 88. Those who disbelieved and hinder (men) from the Path of Allah, for them We will add torment over the torment; because they used to spread corruption [by disobeying Allah, and his Messenger of Allah [SAWW](PBUH) themselves, as well as ordering others (mankind) to do so].

Hazrat Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "Everyone of my Ummah will enter Jannah except those who refuse". He was asked: "Who will refuse?'' He (PBUH) said, "Whoever obeys me, shall enter Jannah, and whosoever disobeys me, refuses to (enter Jannah)".

[Al-Bukhari].

Abdullah bin Masud (May Allah be pleased with him) reported: I can still recall as if I am seeing the Messenger of Allah  [SAWW](PBUH) resembling one of the Prophets whose people scourged him and shed his blood, while he wiped blood from his face, he said: "O Allah! Forgive my people, because they certainly do not know". 

[Al-Bukhari 09, Chapter 92, Hadith # 384]. 

Lesson : as mentioned above in Surah An-Nahl Ayat 88. because they used to spread corruption [by disobeying Allah, and his Messenger of Allah [SAWW](PBUH) themselves, as well as ordering others (mankind) to do so]. The word Ummah here stands for the community which accepted the invitation of the Prophet [SAWW](PBUH), that is to say, the people who on his call embraced Islam. Out of this community who follow him faithfully will go to Jannah.