The Truth means "The Ultimate Reality".
You know, the way things actually are.
If you believe there is reality or truth at all, God is what makes these things realities and truth. God is The Foundational Reality. Eternal. Always was, always is.
See, truths and realities are relative. They are true for a time in relation to something else. They come, they go, they are not eternal. The Truth is always what it is.
That is what God means, and it is not a created thing. If your conception of God makes God a created thing, you are not actually looking at God, but something else. An essential quality of God is that God is uncreated. Another essential quality of God is that God exists.
Not only is God true regardless of what anyone says or what academics think about it, but the theologians or academics themselves understand God in this way.
All atheist arguments are contingent on redefining God to be something other than what God is. Monotheists have been making the same arguments against little g "gods" for thousands of years. Early Christians were accused of being atheists.
But while an atheist deludes themselves into thinking they have no gods, the monotheidt acknowledges The One True God. That is, The Truth Itself.
If you don't believe The Truth, you are adopting a foolish and self defeating position. It also makes you as nonsensical as the strawman gods you refute.
To say, "There is no God" is to say, "It is the truth that there is no such thing as truth".
To say, "Prove to me that God exists" is to say, "Prove to me that it is true that there is such a thing as truth."
To say, "I don't know if there is a God" is to admit one has doubts, and if you have doubts you at least know it is true you have doubts. There is no truth unless The Truth exists.
So everyone knows deep down that God exists.