There is a theory about love I read on Wikipedia once that it is a 3-faceted thing consisting of (1) passion, (2)commitment and (3)intimacy which I think is a very nice summary and one I agree with.
Passion & commitment without intimacy described as fatuous love
Passion & intimacy without commitment as romantic love, and
Commitment & intimacy without passion as companionship
Only the combination fo all 3 produces consummate love, and takes some time to achieve.
In my experience Number 3 has been the most difficult to find and maintain, but WOW, when you have all three it is a wonderful thing. So yes, Im a believer but I think its a rare thing.