By keeping that end in mind you can make certain that whatever you do on any particular day does not violate the criteria you have defined as supremely important, and that each day of your life contributes in a meaningful way to the vision you have of your life as a whole. First things are those things that you, personally, find most worth doing. They move you in the right direction and help you achieve the purpose expressed in your mission statement. In relationships and businesses, effectiveness is largely achieved through the cooperative efforts of two or more people. Marriages and other partnerships are interdependent realities, and yet people often approach these relationships with an independent mentality, which is like trying to play golf with a tennis racket - the tool isn't suited to the sport.
Communication is the most important skill in life.
We spend most of our waking hours communicating. Years learning how to speak. Synergy is everywhere in nature. The principle of synergy also holds true in social interactions. Two people, creatively cooperating, will be able to produce far better results than either one could alone.