One of the most practical arguments used by God's believers in proving the existence of God is the Causal argument. Based on this argument, since nothing in this universe comes into existence or disappears by itself, and in other words, because every effect needs a cause, then the whole world, as an effect, needs a cause and the cause is the God. But on the other side, deniers of God, and in other words, the believers in God's non-existence, raise another question against this idea and argue that: "We, too, know that there is a principle in this world called the Principle of Causality in terms of which nothing in the universe comes into existence or disappears by itself and we, similarly, apply the same principle and ask: So how is God created then? This is because, if this world, due to its order and magnitude, needs to have a creative and immense creator, then certainly the creator himself must in turn have a greater cause and creative creator than himself."
But in answering this question, the divine believers say that God is the First Cause, and since He existed first, He does not need a cause. They also use other arguments such as that He is not an Incident and is an Aseity, and they also claim that because vicious circle and infinite regress are logically absurd, so it is impossible for this causality-based creation not to take into account an origin or a beginning.
Again, divine deniers, on the other hand, in challenging this argument ask that: "If we are, by citing the Principle of Causality, to conclude the existence of a god which is the first violator of this principle, why wouldn't we accept that this universe itself existed first without needing a cause? Why wouldn't we say that the whole universe is Aseity itself?!"
However, in my humble point of view, both of these groups, both believers in God and those who believe in His absence, have made an unfortunate mistake in the logic of their reasoning. On the one hand, divine believers have attempted to demonstrate God's existence and on the other hand, deniers of God have expected His existence to be proved so that they start believing in Him. While neither the rational demonstration of Him itself is logically possible and meaningful, nor can the existence be applied to Him in principle, nor faith after the proof cab be essentially considered a faith!
In fact, a small but terrible mistake has been made, and some minor but serious negligence has occurred, which has caused very big debates throughout history regarding the issue of whether or not God exists and how He has come into existence, an unreasonable but very critical mistake that has misled both those who have faith attempting to demonstrate God's existence and deniers who have insisted on their denial due to the former group's inability to accomplish their attempt.
There is a fine point to be noted, which has unbelievably been ignored by even many great and well-known philosophers and thinkers, that has been resulted in not only a gross paradox between the notions of the First Cause and the Principle of Causality but also very intricate but ill-founded statements and labyrinthine but dead-ending methods speculated to eliminate the paradox. The book explains the paradox and eliminates it through a logical approach.