A relationship can not be successful without this one thing, what is it?

Well, I hear that you think there is one key answer, but I don't think it's really as simple as that. I'll describe the range of things that I think are essential, but which is the most important depends on how you're looking at the issue AND the individuality of the people concerned. 1. Loving and respecting oneself. Without this, one spends all the time trying to be who you think the other person wants you to be, so nothing really 'meets'. 2. The capacity for empathy, being able to get a real sense of how someone else is feeling without having to experience that as a criticism or praise of oneself 3. Feeling capable of surviving alone - so you do not NEED the other person but are choosing to be with them EDIT: I'm really curious about the thumbs-downs. Almost every answer has tried to answer the question from their own viewpoint, and I can't think what the TDs are meant to indicate. Should any of those responsible care to enlighten us, I'm sure most of us would like to know.

For a good relationship I think you should both have the same values. You should have goals that you work on together. It helps if you are of the same religious background. There is a saying " those who pray together stay together. " People say these three little words" I Love you," and think that is all it takes. Those are very powerful words. If you don't mean them they can be the most destructive words. They say opposites attract, well that can be true. I have seen the most unlikely looking couple and wonder what they saw in each other. They are like two peas in a pod. They are a half of each other. Their differences compliment each other. You have to be forgiving. Here is my formula to follow: The three Cs Communication Compatibility Comedy-----Laugh and have fun together.

TRUST!!!!!!!!

everyone knows it's TRUST. If you don't, then you WILL one day. (maybe)

A sex-swing.

Both of you have to be ALIVE if the relationship is going to work. Dating a dead person has some serious drawbacks and things deteriorate rapidly after that initial honeymoon period.

The correct, and obvious answer, is mutual ATTRACTION.

Teamwork. No one individual can hold up a relationship more than the other, it's a two-way street all the way. Both persons need one another (both active & willing to WORK for something worthwhile) to have a strong & successful relationship. Sure there are plenty of couples out there where one person is not pulling their weight as they should, so the other picks up the slack but eventually that person will get extremely tired and fed up and the relationship then begins to crumble. Both individuals have their own individual purpose only to have something so beautiful & valuable emerge when joined forces.

Commitment, being willing to compromise, trust, honesty, respect, love. I don't know which is most important. That you actually like each other maybe?