We have evicted God from our life. This action has great consequence for oneself although the reason for evicting God could be as simple as convenience. Convenient to live a life we define.
The dilema of God's existence or inexistence is of great importance. For example, if God does not exist, human beings and human history can have no purpose other than the purpose they chose to give themselves. This can also be a purpose which is imposed on humans from those who have the power to impose it. This problem also is of great importance as what one believes is what shapes a person.
Ideas has consequences. Whether we believe in a truth or a lie is important. It has ramification as to how we treat others and how we live our lives. It can make us cruel or compassionate.
First to set the context, we humans along with other beings in the world do not have in themselves the reason for their existence. For example, I depend on my parents, and now on the air I breath, and on the food, and so on. Our world is simply the real totality of individual beings, none of which contain in themselves alone the reason for existence. So, in order to explain our existence, we must come to a Being which contains within itself the reason for its existence.
Second, the existence of God also has profound implication for the moral standards we set ourselves. If God's existence is agreed then God is the moral law giver. Else we define our own purpose and we define our own moral law or look for a State to provide the law. In essence, most of those who don't believe in the existence of God or a moral law giver, it is themselves who define the moral law. This is Self Referencing Morality. Below is the expert from the debate between Fr. Copleston and Bertrand Russell where Russell comes to the same conclusion.
Russell: You see, I feel that some things are good and that other things are bad. I love the things that are good, that I think are good, and I hate the things that I think are bad. I don't say that these things are good because they participate in the Divine goodness.
Copleston: Yes, but what's your justification for distinquishing between good and bad or how do you view the distinction between them?
Russell: I don't have any justification any more than I have when I distinguish between blue and yellow. What is my justification for distinquishing between blue and yellow? I can see they are different.
Copleston: Well, that is an excellent justification, I agree. You distinquish blue and yellow by seeing them, so you distinguish good and bad by what faculty?
Russell: By my feelings.