Arguing about beliefs is foolish as they are not based on objective reality and do not have an answer that is perfect enough to defend. However, there are some beliefs that no matter how true or untrue in fact are highly beneficial to accept as absolute, unchanging facts.
All Men Are Created Equal
This should be more of a popular American expression than it is. Despite having supposedly built off this concept, America is still plagued by elitism from every facet imaginable. Sure, there isn't the landed gentry ruthlessly keep the poor at their most miserable in a highly feudalistic society, but socially and culturally we have "the best" "the ok" and "The less." For yourself, I suggest even if many people are born with advantages internally that give them more potential than others--you should still believe that all men are created equal. That you can do anything I can do and vice versa. This will get rid of the excuses in your head that you can't do something because of who you are versus who someone else is. Watch Rudy for a perfect example of this in action.
No One Enjoys Being Sucked Up To
Some people honestly do love to watch people act like less human than they are and treat them like they're better. Yet, if you never allow yourself to believe these people exist, you'll never be tempted to get your boss to like you by acting like a stooge. Sure, you do need him or her to like you, but not the stooge way. You'll do it by being the best, or the nicest to fellow employees, or just an honest person. This applies as well to dating. It's easier for guys to understand no girl wants you to act like some doormat, but for girls as well it's better to believe no guy wants you to be his doormat even if he does because in this you'll never be tempted to be less than anyone else.
You Are No One's Victim
In reality, people are other people's victims all the time. There's mass murder going on, mass sexual assault, mass horrific crimes against humanity that go unanswered. While I'd wager less of those people are on this site than not, you should never allow yourself to believe someone has the power to crush you. Even people above you can fire you..even your lover can cheat on you with someone "better looking" but they can't crush you. You aren't the victim if you don't accept that they ever held that kind of power over you. They dissapointed you, but they did break you.
You Only Live Once
Cliche, yes but more true than people are willing to accept. Every day you walk on this Earth is one less day you have to walk on this Earth before you die. Every moment you waste being anxious is one less moment you have before you die. Every time you sit in your room weeping is another hour of your life you have given up for this person that you will never get back because you will die and there is no cash back policy on life.
Nothing Anyone Else Thinks of You Matters
People are generally on board with this but they are reticient to commit 100% to the belief as a fact. Every time you catch yourself wondering what they think or holding back what you are thinking because it will come off awkward or not funny or mean or inappropriate (there are certain exceptions to this one) say it anyway. You have to get used to saying whatever you feel like. It's more unlearning than learning but regardless it feels like a muscle that you're developing to the point where eventually you'll be running your mouth with your ideas without even being able to think about how it's recieved. Same goes for when you "think back" on what people were thinking of you when the moments already long passed. Say no I will not dwell on this negativity and turn to something positive. It will eventually stick and you'll have a hard time remembering when your life was filled with more negative chatter than positive.
You Have No Real Problems
You have real problems, but it's better to believe that your problems pale in comparison to what other people go through. Having a blessed life starts with believing you have a blessed life. A mansion can seem like nothing if you believe you have a problem filled life. A little shack on the beach can seem incredible if you live for the moment. Accept the belief that if you're healthy and if your family is healthy you HAVE NO PROBLEMS. Every problem you think you have is a game your mind is playing. Again, this is partly true partly not. Sometimes you have very serious problems, but in realizing that your life even it's bad parts is better than it could be potentially you never get phased but the twists and turns.
Something I'm doing for 2016 is pushing love and connection to others as a very important part of life. We can exist alone and be happy, this is true. A man can exist in the wild and survive. Yet, living in communities is as much a gift now as it was during the beginning of Man. Socially interacting with others and pushing that interaction to romantic love is the ultimate achievement of our ability to speak, hear, and touch. Maybe we don't actually have the ability to "love" as we believe it and instead we're just labeling an over-attachment to another for emotional stimulation something pretty to make ourselves feel better, but it's better and gives life more meaning if we accept the belief we can love each other.