"By Him in whose hand my soul is, you will not enter paradise unless you believe and you will not believe unless you love one another." (Sunan Abu Dawud, Adab, 130) Accepting something whole heartedly and believeing it sincerely is called iman (faith). Faith according to İslam is to sincerely believe that the message prophet Muhammed(s.a.w) delivered is from Allah and that it is true.