Having worked with hundreds of couples over the last 40 years, I have developed a set of beliefs or ideas which, if adopted, help to ensure that a relationship will last. One of the most important is: Arguing helps nothing, so don't do it.
I like to say that I never met the person who started the fight! When two people argue, each of them believes that he or she is merely reacting to something the other one did or said. Neither one believes that they started the fight; but it started somehow, didn't it?
It is better to be close than it is to be “right.”
Blaming each other for the argument is counterproductive. So is trying to change the other person's opinion. Most couples who argue, argue about whose perception is "correct," whose way of doing something is the "right" way, and so on. The only possible outcome of these arguments is that someone will be "right" and someone will be "wrong." Do you know anyone who enjoys being wrong? Most people will fight tooth and nail to avoid being "wrong."
Commitment is the Foundation of the Therapy
Commitment implies that you are in the relationship "come Hell or high water," barring certain behaviors your partner might do such as having an affair (although I have seen a number of relationships recover from those, too). Unless each partner believes that the other one is committed, they will not feel safe to take risks in facing, addressing and working out the real, underlying issues that affect the relationship.