Arabic text
عن أبي هريرة رضي الله عنه قال: سُئِلَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ عَنْ أَكْثَرِ مَا يُدْخِلُ النَّاسَ الْجَنَّةَ، فَقَالَ: «تَقْوَى اللهِ وَحُسْنُ الْخُلُقِ»، وَسُئِلَ عَنْ أَكْثَرِ مَا يُدْخِلُ النَّاسَ النَّارَ فَقَالَ: «الْفَمُ وَالْفَرْجُ».
Translation
Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) was asked about the foremost deed that leads people to Paradise, and he replied: "Fear of Allah and good character." Then, he was asked about the things that most lead people to Hellfire, and he said: "The tongue and the private parts."
Explanation
The Prophet (may Allah's peace and blessings be upon him) pointed out that the greatest means that lead one to Paradise are: Fear of Allah and good character. Fear of Allah (taqwa) is to make wiqāya (shield) between oneself and the punishment of Allah, by observing His commands and prohibitions. Good character: by having a cheerful face, doing good to others, and averting harm from them. And that the greatest causes for a person's entry into Hellfire are: The tongue and the private parts. The sins committed by the tongue include: lying, backbiting, and tale-bearing. The sins committed by the private parts include: adultery, sodomy, etc.
Source: HadeethEnc.com