The design argument leads to or supports a belief in God because, if you take it seriously, it shows that nature must have been created according to a plan. According to advocates of this argument, the fact that life exists at all is simply too improbable to have occurred by chance. They also say that some aspects of life, like the complicated structure of the eye could not have come about by chance because any slight change in the eye would make vision impossible. If you accept these arguments, then it follows that someone or something created the universe according to a plan. That someone (to be so powerful) must be God.