Some people say that it does not matter what you believe as long as you are sincere. This is a popular cliche but it is full of practical contradictions when put to use.
What you believe. what controls your decision making, what causes you to react to others opinions is called a world view. There are many world views. They cannot all be true, because they contradict each other. Once you have a contradiction, logic comes into play. You really do not want to be known as one who cannot think logically.
Now you must make a decision. If one believe contradicts another, then they both cannot be true. Now it could be that neither is true. So the search goes on to find that which is true.
What might be a means available to find the true one? We introduced logic above. If logic helps us to find truth, we need to ask, where does logic come from? Is there some kind of entity in the universe from which logic emanates? Since there seem to be laws of logic, the characteristics of these laws should help us to eliminate some world views.
An example is if a concept or object has an identity (The law of identity), it cannot be two things as the same time (the law of the excluded middle), and cannot have characteristics which are contradictory to its identity (The law of contradiction), then that identity must be specific. This rules out random identity options. This rules out any world view which holds to the concept of random truth.
This conclusion is an application of the laws of logic. This application rules out such world views such as Atheism, Naturalism, Darwinism, and Humanism.