The proof of the existence of G-d is based on the creation and ways of the world, specifically, the physical world we live in. The way to find closeness to G-d, which leads to never doubting Hashem, is by working on the duties of one's spiritual heart. Now, the point of this essay is not to convince non-believers that a G-d created the world. It is to show the people who already believe, to realize and appreciate how great the ways of Hashem are, and what the benefits for believing are, and hopefully to light a spark inside a doubters mind that may just lead them on the right path to Hashem, according to the Chavos Levavos, Duties of the heart. .
Nothing can make itself. That is a fact. So how come people believe that the world made itself? Some may say, "well atoms mushed together and created life" but how were those atoms created? Where did they come from? Same thing applies to G-d. If someone says they believe in the big bang theory but not in G-d, they sound like a complete fool. They are believing that something physical, like the world, was able to create itself from nothing, but they think it's impossible for a G-d to have created the world because it's impossible for nothing to make itself. It totally contradicts what scientists believe, but they are too blind to see it. The Chavos Levavos explains, that either something was made by itself while it existed, or after it was created. and both are quite impossible. If something can create itself while or after it exists, it is already created so it cannot create itself again which proves the world must have been created by something out of our own human knowledge. .
Trying to show an Atheist G-d, is like trying to explain to a 3-month-old baby algebra. you can't. They are not able to understand it. The baby must grow up and find its knowledge themselves, just like atheists must find G-d on his or her own, but help is needed along the way, in both scenarios.