In my own opinion, I would say "God" is a word synonymous to "Mystery".
First of all, God exists. An atheist would never wanna believe it. Deep down in the hearts of some Philosophers and even atheists, who don't believe in the existence of God, they strongly have that feeling about His existence. They just don't wanna acknowledge it.
Now, let me talk to you reading this. How do you think it's possible for you to have a mind conversation with yourself, or how come you dream dreams and sometimes you get revelations from them, or how is it possible you open your heart to pray (to whoever or whatever you pray to) and you have this real conviction that someone is listening? Have you ever gazed at the sky for a moment? You would be filled with inner curiosity, anxiety and laxity (slackness or helplessness) whether you admit it or not.
He really does exist, but He remains a mystery. He was before the beginning of time. That should be when? Nobody does know really. You know why? It is because 'Time' itself is a created entity. If you were to go back in time, you would still have an infinite period or amount of time before God began creation! So, it is pointless to start going back in history, trying to figure out when exactly. God was in existence before time itself.
Man is way too insignificant to analyze or comprehend God. Whatever he knows is because God wants him to, else, the little he knows would still be a mystery to him.
Now, talking about God being a mystery, let's carefully consider it, MYSTERY:
*M- Majesty. This is the quality of being great and mighty. That is one way to try to describe God. He is indescribably great, glorious, gracious and good.
*Y- Yahweh. By the way, you should know that God has no shortage of names. He is actually called by so many different names in the Scripture. But one of these names is spectacular, and that name is Yahweh.
Did you know that the name Yahweh (yah-WEH) occurs more than 6,800 times in the Old Testament? It appears in every book but Esther, Ecclesiastes, and the Song of Solomon. It was said that, "As the sacred, personal name of Israel's God, it was eventually spoken aloud only by priests worshiping in the Jerusalem temple. After the destruction of the temple in A.D. 70, the name was not pronounced. Adonay was substituted for Yahweh whenever it appeared in the biblical text. Because of this, the correct pronunciation of this name was eventually lost. English editions of the Bible usually translate Adonay as "Lord" and Yahweh as "LORD." Yahweh is the name that is most closely linked to God's redeeming acts in the history of his chosen people. We know God because of what he has done. When you pray to Yahweh, remember that he is the same God who draws near to save you from the tyranny of sin just as he saved his people from tyrannical slavery in Egypt."
*S- Sovereignty. In terms of Politics, this is "The state of making laws and controlling resources without the coercion of other nations.
Isn't that the nature of God? From above, the universe is being controlled without the threats of anybody or the force of any kingdom. His laws stand firm from everlasting to everlasting.
In terms of a ruler, it is a "Supreme authority over all things." God's authority is supreme, higher, and greater than even that of the kingdom of darkness. Remember, just by breathing, man became a living soul, and by just speaking, everything we ever see came to being. There's no other authority in the heavens, on earth and beneath that can be compared to His.
Now, in terms of a person, sovereignty is "The liberty to decide one's thoughts and actions." Very well! He knows our thoughts, He could choose to decide our thoughts and even more, because He knows us more than we even do.
*T- Trinity. Did you know that God is three-in-one in nature and personality, yet He is one and only? A mystery, right? Jehovah, the Father, is the God we always talk about; His Word became flesh, which is Jesus Christ, who was born in the physical for the redemption of humanity; and then His Jealous Holy Spirit (jealous in the sense that, He doesn't contend with man, He takes over man if only he would let Him in, and He shares not His glory with anyone). This is the Spirit part of Him, living in us, guiding, comforting and revealing to us more about God.
*E- Eternity. Eternity is all about endlessness, limitlessness, and timelessness. This is the nature of the One on the throne. He has no end, His kingdom is for everlasting; He is not limited by any force, He is mightier than our imagination; and He has no time, 'cause time has no effect on Him. He created time in the first place. So, without Him, there wouldn't even be time.
*R- Resurrection. Christ said, "I am the resurrection and the life..." He was killed for the crime He never committed, and what happened on the third day? He resurrected! Life is in His palm, so, death definitely shouldn't have a told on such a Person.
*Y- Yeshua