So, a huge question that always pops up is how do we exist, or why do we exist? However, what is existence itself? A famous term is "Je pense, donc je suis", or in English "I think, therefore I am". However, this does open up some questions. Here are a few that I have:

• What are thoughts exactly? Are they made up of matter? If not, do they really exist? Is existence determined by matter? Or is existence merely attributed to the idea that it exists? In other words, do we exist merely because we say so?
• You can only read your own thoughts. Therefore, you can only confirm your own existence, assuming that existence is indeed the capability to think. I for example don't know if other people truly have their own thoughts, or if other beings are merely constructs of my mind, since my mind determines what I feel, see, hear, etc. I could really be interacting with a sort of fake world of my own creation. Now, is our brain capable of creating such complex worlds and constructs in the first place, though?
• Once we are dead, what happens then? Assuming there is no afterlife, that means we cease to exist presumably. But what of our corpses? That leads back to the question of matter. Since our corpses would still exist at least in the short-term, is the decision is matter than we would still exist, but if it's of thoughts and minds that means we wouldn't.

For me:

Sit#1. God is real and therefore we are fake
Sit#2. We are real and since matter cannot be destroyed we are continually recycled until we get this. In this instance we are in a universe in which life is rare. Perhaps in other instances that is not the case
Sit#3. Nothing is real and we’re just a hypothetical scenario being played out in real time

Idrc if any sound stupid or care to explain too much more than what I presented. But those are what I believe are the 3 most likely scenarios that make up this reality

I think God is the creator of all things and whatever he creates is existence.

So, what about things that humans create then after being created? Do those not exist since it was not directly created by God?

God created humans and humans created these things so they exist.

He exists but he's always been around. Male is the default gender IMO.

Philosophy ?　

So, what about ideas then? Do ideas exist?

The Cogito was taken to task by many philosophers but the most thorough shellacking came from Friedrich Nietzsche in Beyond Good & Evil. There are intrinsic assumptions which were exposed quite fantastically in that work. The short version is that the Cogito fails fantastically to establish existence of self.

Your question seems less about existence and more about the resolution of the Platonism / Nominalism debate.

https://philpapers.org/surveys/results.pl

Whether or not abstract things exist is at the epicenter of that debate. Do numbers exist? Do shapes exist? Do bizarre creatures concocted by one's imagination exist?

I find that religious folks tend to side with Platonism; that numbers and imagined things exist. 

Personally, that's ridiculous. Of course numbers do not exist, shapes do not exist. These are merely abstract constructs of one's mind. No more real than the boogeyman who stalks the dreams of children. It's electrical-chemical phenomenon of our brains. To say that something exists is to say that it is real, or to say that it is part of reality but our imaginations represent the imaginary or non-real. The position seems entirely bankrupt to me.

I think the issue Platonists have is thinking that properties are the same as objects. Objects have properties. An objects has properties such as shape, size, color, texture, yet Platonists think shapes are objects. That is their folly. An object can be [insert shape] but an object cannot be an [insert shape] because shapes don't exist. Objects which are circular exist, but circles do not exist. You cannot walk into the woods and pluck a circle from the weeds.

There is ample philosophy about this already and I think I've said enough to clarify my position. This forum is probably the worst place for this type of discussion. I attempted to describe the difference between intrinsic and extrinsic to somebody over several posts on another thread and the user failed miserably at comprehending this elementary distinction. I recommend reading actual philosophy (which I admit can be mentally exhausting) if you wish to further your own understanding of this debate.

I think the earth exists and humanity is its cancer and will kill it

And obviously, as a decease we also exist to kill the planet, but I don't believe there is an existence after death there is just nothing. And I also think the universe and the worlds in it are a mistake that should have never happened. There should have just been nothing.

Thoughts to the best of our knowledge are signals - electrical and chemical. So ultimately, thought have a physical form and aren't anything "ethereal".

Second question is unanswerable because with the premise that any answer/informatio you are given could also be a part of this "fake reality". It's an interesting question to debate, but it's not one that can ever be answered.

When you die, the aforementioned chemical and electrical signals seize. We might be able to "resume" this through resuccitation, though, but ifthat isn't done soon enough, your thoughts and your state of existence will be irreparably damaged.

These might be boring answers, but some philosophical questions simply have answers. What really messes me up is continuity of consciousness.