Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "By Him in Whose Hand is my life! You will not enter Jannah until you believe, and you will not believe until you love one another. Shall I inform you of something which, if you do, you will love one another? Promote greetings amongst yourselves.''
: Iman is a prerequisite for entry to Jannah. Whereas mutual love among Muslims is complementary to it, and this quality can only be attained by giving a social character to the Islamic form of greeting, that is to say, `As-Salamu `Alaikum.'
As'salaam alaikum all =).