Two questions:
How did you come to understand God is invented?
What observations have you made that those who do believe God make Him their only purpose?
The beliefs of Christians are based on a "holy book" full of contradictions and lies. It's just a bunch of mythology and even then Christians can't even agree on which brand of Christianity is true. There are over a billion Roman Catholic Christians (1.3 billion to be exact), about 900 million Protestants, and approximately 350 million Eastern Orthodox. Many of the Christians of these different traditions i.e. brands, will condemn the members of the other brand/"denomination", to hell. Denying that those "Christians" are actually Christians. They can't even agree among themselves, as to what type of Christianity the so-called "lost" should turn to for salvation. And if that wasn't enough, the vast majority of Jews reject Christianity.
It's all mythology. Is it possible that a personal GOD BEING exists? Maybe, but I just don't have enough information to come to that conclusion. I can't affirm or believe that there is a personal GOD ENTITY, until I get access to that information/evidence. If you ask me "Did president Biden eat a strawberry cheesecake today?", I would answer, "no". I have no reason to affirm or believe that he ate a strawberry cheesecake today. Is it possible that maybe, he ate some cheesecake today? Yeah, maybe he did, but I don't have enough information right now to lead me to conclude, affirm, or believe, that he did, hence I don't believe. I'm an "acheesecash"/atheist, when it comes to Biden eating cheesecake today.
You're telling me the Christian deity is real, but your evidence is horrible. Pathetic. Why should I believe this? Right now I'm an atheist, a person who doesn't affirm or believe in the existence of a GOD BEING or personal deity. However, I'm maybe 30% open to the possibility that there is a God. That GOD is EVERYTHING (pantheism), seems more likely to me that the Christian version of deity. That was Albert Einstein's belief. He was a deist and pantheist, appealing to the philosophy of Spinoza. Einstein stated that he believed in "Spinoza's God". Einstein didn't believe in life after death, and niether do I, but he did believe in God. I'm an atheist that leans towards Spinoza's God, but I don't affirm or believe that because I don't have enough evidence, hence I identify as an atheist.