I felt strongly, after reading the Old testament in the 1970's, that the God described in the Bible did not exist.
Years went by. I flew past the edges of New-Agey stuff - universal spirit, animal spirit guides, ancestor spirit guides, past lives. None of this took. I flew by calmly and without getting too far inside the periphery, close enough to see and feel it, not so close that I lost sight of reality.
Within the last ten or twelve years my interest in truing up my understanding of reality with actual reality has increased. Examination of mass media and how they market to us, the use of language for good and bad, politics, political theory, ideology and government. Finally, I spent some time with self-paced courses in philosophy of religion and science.
Finally, I've spent my own time examining the arguments for God, evaluating the truth and validity of the various arguments. A light review of how the Old and New Testaments were written was also beneficial, as was some reading on the creation and growth of Christianity, through the Roman Catholic Church and the Protestant Reformation.
I've done my due diligence. I won't get sucked in to "sophisticated theology" or other dodges that have been stood up as arguments for God.
There are no good arguments for the existence of God.
Dealing with the world as it manifests itself remains the only reliable way to navigate through life. Living as if this is the only life we have is the only rational way to live.