There could be a number of different reasons for this. Aldous Huxley, himself a well known atheist and author explained it this way:
"I had motives for not wanting the world to have a meaning; consequently (I) assumed that it had none, and was able without any difficulty to find satisfying reasons for this assumption. The philosopher who finds no meaning in the world is not concerned exclusively with a problem in pure metaphysics, he is also concerned to prove that there is no valid reason why he personally should not do as he wants to do, or why his friends should not seize political power and govern in the way that they find most advantageous to themselves....For myself, the philosophy of meaninglessness was essentially an instrument of liberation, sexual and political."
Thus wanting to have a philosophical basis for avoiding moral sanctions and/or accountability to a higher being indeed motivates some although they may not be as frank as Huxley was. This is why so many seem particularly keen to cast moral doubt upon certain actions of the God they don't believe in. If He exists and if He is a moral being then they may have to to Him. Thus behind much Atheism is rebellion, although certainly not all. But, as Rocket Scientist Joe Sabeney put it, they "look in the mirror and see their god," thus they will not be accountable to a higher power and can essentially do as they please, as directly stated by Huxley. Intellectual objections could in these cases become a smokescreen for the real issue, whether the person is aware of it or not.This motivation to get rid of God to avoid accountability is a common theme. Some do it consciously and state it directly, others unconsciously as they are taught that the universe evolved and has no ultimate meaning and that this is just 'tough luck' and so draw their own conclusions and write their own morality.
This, of course is not the rationale for all who become atheists. Nor to state it does this imply that anyone is being dishonest in claiming any other reason. There are probably quite a number of different reasons. Another could be hurt suffered at the hands of a person or persons who claim to believe in God, and so they blame the almighty creator, rather than the person who did them wrong. Not all who claim His name are true to Him.
Romans 1 contains a similar explanation to that given by Huxley. People make a choice not to believe in God, whose handiwork they see, and whose handiwork they themselves are.
Romans 1:18-25 (King James Version)18For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;19Because that which may be known of God is manifest in them; for God hath shewed it unto them.
20For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:
21Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.
22Professing themselves to be wise, they became fools,
23And changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and fourfooted beasts, and creeping things.
24Wherefore God also gave them up to uncleanness through the lusts of their own hearts, to dishonour their own bodies between themselves:
25Who changed the truth of God into a lie, and worshipped and served the creature more than the Creator, who is blessed for ever. Amen.
Many such people claim to be both rational and tolerant. Yet they frequently behave in ways which exhibit neither quality, thus supporting The Bible's claim that their lack of belief is a choice. Of course most in our current age do not descend into idolatry of this kind, but they do deify human reason and say 'man is the measure of all things,' thus indicating their pride in humanity fallen as it is, and in human technology and in science. Quite possibly the vehemence of their denials, the regular evidence of intolerance and of non-rationality, of denial of known facts suggests the truth of the existence of the creator and of the Biblical verdict of rebellion.
God is the creator of the universe. People who believe in evolution believe that God created things and allowed them to evolve.
One God, creator of all things, who gave the Torah.
That God is one and is the creator of all things, including time and space, and that God gave the Torah. See also Exodus ch. 20.
Why People Believe Weird Things was created in 1997.
Jews believe in the One God, creator of all things (Deuteronomy 6:4).
No! He is certainly not! God is our creator and he is the only god there is! Also, if you say 'Oh my God' all the time, why do you say that? Why do people get angry at a god that they don't believe in?!
What makes up who you are? Your choices, your decisions, the way you do things, how you think , so many things . Stand up for what you believe in with good reason.
The main basis of African culture is that they all believe that there is one creator of all things.
He was not created. He is the Creator of all things.
People can believe all kinds of things but without proof or some evidence, how do we know it is true at all?
People in England are from may diverse cultures and believe in a great variety of things.
They believe in superstition to explain things that they do not know how to explain.