I don't think man could possibly know the Creator or the plan. That is way above our pay grade. Knowing that there is a creator and that the plan is ever changing, that is a different thing.
As for as religions, I see them as all cults. Used to keep the masses in line and propagate group think. Once they have too many roaming free, another religion comes along to herd them back in.
All of the books are written and published by man. Do you not think they are written for the benefactors and future generation of the writers? The rest are dupes.
I am more leaning to the simulation theory. Our realm is too perfect in a sense.
Now for flat earth. I do not know how far you have delved into the questions presented.
Shape, who knows.
The sun and moon are much closer and much smaller.
Flight maps displayed over the currently used F.E. map run in nice straight lines.
These also line up with emergency landings that have been made that made no sense in the globe flight path.
We see to far. With long range digital telescopes, we are seeing objects up to 20 -50 miles further away than we should. Depends on the air at the time.
Water always maintains it's level.
I spent years looking for a good argument against. It's not there.
The worst part about it is the strawman personal attacks and sometimes outright hatred along with name calling. That only happens when you might be on target.
I would say each of our versions change everyday on many things. Up until 2014, I still had some respect for the medical industry. Up until 2020, I had some respect for vaccines. Up until 2000, I had respect for the justice system. Until I was 3-4, I believed in Santa Claus.