There is what we believe and there is truth. Real truth. And sometimes they are close and sometimes they are not. Depending on how you use truth - either plainly or twisting the world to create a perceived truth, you change your interaction with the world.
Truths can be simple or complex and can be true all of the time or situationally. Simple: The sky and oceans are blue. Death is a certainty. Moderate: I do some harm to the world by living a disposable lifestyle. Difficult: People act in their own self interest much of the time, intentionally or not, including me.
That last one is difficult because we like to think of ourselves as generous, caring, giving - good. And all of those can be true, but at the very basis of that, is the ability to survive. The difference then, is how I perceive the world - as a fight for limited resource or a place of relative bounty. If I see it as the later, I will tend to share more and I will see others, who share less perhaps as less fortunate. And I will see those that work to deny others that bounty as stepping past the bounds that define a good human being.
It is easy to get caught in a race and think in order to win, others must lose. There are those that profit off this mindset and so the race is presented every day, by some politicians, by private agendas, by those who trade in fear in order to control.
Humanity in reality has not survived by "survival of the fittest" for a long time. That was true before we developed civilization, when we we either ate or were eaten. Civilization developed to help us leverage each other to make survival easier. It's about what we can do together - and we serve ourselves by working with others. We defeated much of evolutions tools to filter us out. It's why near-sighted people survived. Vaccination. Food development. Social nets.
A truth: The very act of being selfless (in whatever way you can) can in turn serve oneself and others at the same time.
Another truth: Taking care of oneself is paramount. Self love is different than self aggrandizing or selfishness. It's necessary to continue. It's taking care of the golden goose.
So, all year, but during this season especially (because it is a time held special by many and a time of vulnerability), remember that we are all different and in that we are all equally deserving of a life, happiness and love. Remember that you can get where your going by helping others get where they are going.
Earth's the right place for love:
I don't know where it's likely to go better.
(from Birches, by Robert Frost)