Since I don ' t actually understand how they came to the conclusion of the Big Bang theory being the most accurate model , if I trust them and claim that the big bang theory is the most accurate model isn ' t this actually a belief ? Observation , the universe appears to behave in a predictable way , for example if it didn ' t we couldn ' t mass produce planes because they wouldn ' t fly reliably , we wouldn ' t be able to mass produce mobile phones because they wouldn ' t work . Forensics wouldn ' t be a thing because dead bodies would cool at an unpredictable rate , we couldn ' t trust finger prints and DNA to be reliable indicators of who they belong to , we wouldn ' t be able to build a narrative of a crime scene . Test , the scientific method is the undisputed , best tool for finding things out , what works and what doesn ' t , whats reliable and how reliable it is . Even if something doesn ' t happen the same every time , you can find out how likely it is and have a probability number . Result . If aren ' t going to take the big bang as extremely high probability then we cannot expect our mobile phones to work , anything mechanical to work , you can ' t expect to eat and digest food , and we certainly can ' t recreate a crime scene and put people in jail with a high degree of confidence . tldr You shouldn ' t have a belief in the big bang , you should understand that it is possible to work things out , and through the miracle of the everyday you experience , just going on twitter and reading tweets on your mobile phone requires amazing technology you can be justified in having a high degree of confidence in science . From that you can have a high degree of confidence in peer reviewed , verified scientific theories .