Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “You will not enter Paradise until you believe and you will not believe until you love each other. Shall I show you something that, if you did, you would love each other? Spread peace between yourselves.”

Source: Sahih Muslim 54

Grade: Sahih (authentic) according to Muslim

For ARABIC, click here:

http://dailyhadith.abuaminaelias.com/2012/03/16/hadith-on-love-you-will-not-enter-paradise-until-you-love-each-other-for-the-sake-of-allah/