The process one goes through in trying to prove something must be based on evidence in order to establish a fact. One cannot use any faulty reasoning such as circular reasoning to trying to prove something. Now concerning complaints about the validity of these and similar arguments, let's examine some of the issues that were raised.
As for the material objects in the Universe, it can be established that each one has defined and limited attributes. These attributes make the object in question unique and distinguishable from other objects. Now this pattern of unique, distinct attributes in every object indicates that each object has certain limitations that makes it what it is. It is not an assertion to say that these objects with all of its defined attributes were assigned by something that gave it its attributes because of what can be observed from the object in question.
When one places a barrier on something, then whatever was meant to be blocked or hinder in growth, strength, etc., was given this barrier by someone so that the distinctive qualities in the object can be manifested and given a purpose. So if I am 6 feet tall and look a certain way, the reason why I don't continue to growing till eternity is because of a barrier that someone place that cause my body to grow a certain length. This is the nature of finite objects, that all of creation in the Universe has a beginning and an end, even if something expanding it still had a beginning, negating the possibility that it was always eternal and existing.
In pondering and discussing the issue of whether or not there is a Creator
or were we and the Universe created, the issues of the finite nature of
all of creation must be taken into consideration. To imply or say that
saying that the body parts of a human being is proof of Creator is "assertive"
is to dismiss without right and dismiss with cynicism. What the issue here
is what I am talking about finite creation is really finite creation, and
does this creation has a purpose in its creation. To give the simple analogy
of a car, we can observe how it works and why it works. You can say that
the wheels, doors, steering wheel, etc., all have a predefined purpose
and each of these objects is serving its purpose according to how it was
created. To say this is not being assertive or using circular reasoning.
To look at creation and see the finite quality of it and see the objects
with its defined
attributes, you can conclude through examining it that it was designed with a purpose because it has a role to play it whatever thing it is involved in.
And when an object needs another object to accomplish something, then this in itself establishes a purpose in the relationship of these objects. When hydrogen and oxygen are added, the purpose of this union is to create water. To say this is an assertion is to deny reality. We can see the purpose of the relationship between these entities, and we can conclude through examining creation that all of Creation works in a similar way, i.e., that one object needs another and this in itself of course show the purpose in the relationship of these things. So to question ones use of this argument as faulty or assertive is to say without knowledge nor without a justifiable reason.
On the other end there are those who want to believe that chance has a "chance" of creating what some may "perceive" as according to them as a planned creation, with the need of a creator or plan. Now they want to present an argument of not dismissing the possibility of chance, so to create a tit-for-tat, vain argument that it intended to lead one side to the point of frustration. The atheists for example want to inject in an argument that there can be a realistic chance that chance could of cause all of this, and the "theists' assertion" of the need for a Creator with a plan is just an assertion.
When one is confronted with this type of argument, one always must refer to method of deducing evidence to establish a fact. When Muslims are asked why do we believe in God, the correct answer is that our Imaan (faith) is based on proof not on desires or wishful thinking. To believe in something that cannot be proven is to have blind faith not Imaan. To try to first prove that we and the rest of creation are indeed finite with define attributes, we must then try to prove that was it an eternal entity that assigned these attributes and created all of Creation. Looking at how things develop and work in the world, one can observe any normal occurrence in the Universe and see what it takes for whatever to happen and develop. To conclude that there is a chance that "chance" can be involved is being assertive because there is no proof that chance exists, because what one sees as chance the others sees as creation. Now as for the belief that seeing it as creation is an assertion, one must prove that chance can create something from nothing or that something itself can create something from nothing, and we know that this is impossible. It is Allah alone that is able to create something from nothing, and it is Allah alone who is eternal. So to include an impossibility into an equation and give a possibility the label of an assertion is not being fair. The flaw in the argument of those who suggest that chance exists is very clear to see, because we know for a fact that something cannot created something from nothing, and we know that there is no evidence of chance.
To reiterate, the purpose of having this discussion is not to indulge
in some vain, philosophical debate. The reason why Muslims in the past,
present, and Insha' Allah future raised issues such as the existence of
Allah was because to establish a basis for belief through believing in
proof. Proof can be proven and proof is what Imaan is built upon, not blind
faith. To prove the source of Islam to be from Allah is to leave the Kuffar
or anybody else no excuse to disbelieve in Allah and Muhammad (saaw). We
cannot say Islam is the truth without being able to prove that Islam is
from Allah. Allah challenged the Kuffar to an intellectual challenge in
the Quran, to give the Kuffar a chance to intellectually validate their
kufr if what they believe we true. As we know, the Kuffar's beliefs are
proven falsehood while Islam is proven truth.