No one should care what I “think” about heaven or hell. And neither do I care about what thoughts might flicker through my mind. What I care about and what any human worthy of the title “human being” should care about is the truth. Obejctive reality, truth, does God exist. That’s the difference between human life and animal life. Poor animals cannot consider or seek for transcendent truth. Humans can, and that is the duty and mission of human life.
So flickering thoughts of any human are not useful unless cognizance is lighted and informed by truth, which is found in various scriptures, and dawns within the heart as realized truth, experienced deep within, by the mercy of God.
The Vedas teach that atheists go to hell. But as long as there is breath in the body, each person can choose to pray to God - even if they are not sure He exists, or think He may not exist - and ask Him. Even at the last second of earthly existence. But it is harder when one has spent an entire life of rebellion against Him; not impossible, just much harder.
Better to ask such questions now.
I used to be an atheist. But I questioned, and sought the truth. Knock, and the door will be opened. Seek, and you will find.
Why I'm Catholic (Sola Scriptura leads atheist to Catholic Church)