Your question gets the ball rolling in several directions at once! But before we find out just where the ball stops and which court it finds itself in I must first answer with a question. Are these human beliefs related to or rooted in history, mythology, religion or science?
There is a vast range of human experience which has led to exceptionally strong belief systems - Christianity, Islam, and most religions for example have moral precepts which form realities for practicing religious people today. These belief systems may have their origins in what might be called supernatural/transcendental events which the majority of us may think surreal, in the sense that we cannot hope to understand how they occurred. I may think many religious rituals unreal because they don't make sense for me - I choose not to have them in my framework for everyday living, ie my everyday reality.
If I say something like ' God will look after me ', what am I saying about my own sense of self reality? That I owe it to an omnipotent Being who will do with it what He/It chooses?
On the other hand I may be a complete believer in myself, (solipsism). Everything I do is determined by my own sense of reality, the I, and I gain that sense of reality by contributing to society in a plain, materialist fashion. I trade my sense of reality with others, as in a market place, and there's little room for conjecture, debate, speculation on anything other than the here and now, survival in it's brutal form.
As humans we have to make a continual assessment of the tension between belief and reality. Extreme choices can be made and in certain situations the consequences can be dire. If I believe in an afterworld for instance I may want to volunteer as a suicide bomber and become a martyr. If I believe in freedom of personal defence I may want to arm myself to the teeth!!
For those individuals in power in various countries their decisions (based on beliefs) can become an overwhelming reality for millions, religious or not.
Personal reality is a tricky term to define or understand. Belief systems can influence it but often stronger cultural conditioning becomes the bedrock for most of our worldly dealings.
Your philosophical question should be examined further in a hub/hubs. There are some good philosophy books around at the moment - not too heavy - and they help you expand your ideas and thoughts. One such title is The Complete Philosophy Files by Stephen Law, a British philosopher.