I think everyone has made some excellent points - I absolutely agree that marriage takes commitment and effort as well as a lot of love. Soulmate can be an excuse for ducking out of responsibility - MLCers are adept at twisting words and concepts to their own ends. Yet another reason for never ever arguing with them!
I do think that there are people to whom we are deeply attracted on every level of our being - and it certainly feels like a soulmate. However if we are co-dependent it can also feed into that.
I think my xh and I were well suited, very much in love, and had a deep connection. But I can live without him, even if I miss him, the person he was, not the strange man wandering around out there in his own reality. [His right btw, just saying]
What it has done is make me very very picky about the idea of anyone else. Not because I believe that there is only one [although there may be for some people] but because I don't want anything that feels less good to me, to fill any void.
The other problem with the idea of a soulmate [which part of me likes a lot] is that I am drawn to the idea that we complete ourselves, not another person. Another can complement us, but we need to validate and find contentment from within, not from being linked to someone else. Singleness has its own attraction, and is very counter-cultural. My kids think it is cool!! my 02