From The Saying of The Messenger (pbuh ) (11)

"قال رسول الله صلي الله عليه وسلم" : "والذي نفسي بيده لا تدخلون الجنة حتى تؤمنوا . ولا تؤمنوا حتى تحابوا . أولا أدلكم على شيء إذا فعلتموه تحاببتم ؟ أفشوا السلام بينكم "الراوي: أبو هريرة المحدث: مسلم - المصدر: صحيح مسلم - الصفحة أو الرقم: 54 خلاصة حكم المحدث: صحيح
Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "By Him in Whose Hand my soul is! You will not enter Jannah (paradise ) until you believe, and you shall not believe until you love one another. May I inform you of something, if you do, you love each other. Spread peace amongst you " (Muslim)
Commentary:
In this Hadith the messenger of Allah ( peace be upon him ) tells us that the religion of Islam is the message of peace and love. He (pbuh ) wanted to build a nation which is based on peace and love .He motivated us all to love each other for the sake of Allah (pbth ) and as we all know that one of the divine names of Allah is "The Peace " and after praying we say "O Allah you are the peace and from you we have peace" and we saw that Allah (pbth ) loves those who love each other in the sake of Allah (pbth ) and we knew what Allah prepared for them in the day of Resurrection .The messenger of Allah swears by Allah that we will not enter paradise until we believe (of course in Allah the only unique God and in Muhammad as the last and the seal of all messenger and believe in all his prophets and messengers and all his books and so on ) and we will not believe until we love each other. So the love leads to the belief and the belief leads to paradise and at the end of the Hadith The messenger guide us to do something if we do it we will love each other that is "spreading peace " as an only way so He (pbuh ) taught us to greet each other saying "As Salamu Alikum " which can be translated into "Peace be on you" to any one who I know or I don't know .That means "I hope from Allah to grant you peace to live a happy and a peaceful life " By the way "peace be on you " was the greeting of all prophets and messengers of Allah from Adam to Muhammad (peace be upon them all ). The Messenger of Allah taught us that communities societies are built on peace and love and they lead us to happiness and progress . Thank you all and may Allah guide us all to peace and love .