It is narrated from the previous chain that the Noble Prophet (peace and blessings be upon him) said: By Him in Whose hand is my soul, you will not enter Paradise until you become complete believers, and you will not become complete believers until you love one another. Shall I not tell you of something which, if you do it, you will love one another? Spread the greeting of peace among yourselves.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10431