The future is not existing - only that a future will come exists.
This is absolutelly not self-evident. Creator and creation are different things - and it's very mysterious if the creator was existing in a nothing which we are now. It's possible to see in god all existence per se - but not the existence of god - except god created himselve what also could be possible in reality - but we had nothing what could give us any plausible idea about.
If we simplfy the problem and say everything what exists are songs - so we have an outside of this songiverse which in the reality in the universe not exists - where is a song as long as it is not sung - and who sings you and me and all the myriads of other songs? And how are we able to compare our extremely fluid form to exist with any "hard matter" or "hard facts" which only reflect us and gives us new directions without any possiblity for us to know anything about?
Let me say it this way: Your problem is not not to be able to think about this what I said to you. Your problem is you do not like to think about and you like to tell others - me in thsi case - what they have to believe, because somewhere is written something on a piece of paper. But even the bible itselve is sometimes onyl a very good book to use it under a short table leg before to learn to repair the table leg and to understand what's written in the bible.
Nevertheless: Your idea - a very wide spread idea all over the world - agnosticism is only a kind of atheism is more than only totally wrong, what everyone is able to tell you who never saw god and believes in him.
And it's by the way indeed unimportant for Christians to know whether really nothing had been "before" god created all energy and matter, all time, all space, all natural laws and ... (=all what we need to exist here). But we are not able to say anything else than nothing about this. And if something looks like nothing, smells like nothing, gives not any imagination or idea or fantasy like nothing and so on and so on and so on - so why not to call it nothing? And why not to think only god was able to bring this nothing into an existence? But if someone thinks so then it's totally normal to ask "Was god existing when he made everything out of nothing"? And believe me: Such questions will not let go the world down only because you feel not comfortable with such questions.