* Part 1: an anecdote
I recall an episode in junior college (senior high), when my class was taught that the factorial of zero, i.e. 0!, is equal to 1. Some students, in their excitement, started trying to prove that fact. Some even thought they succeeded.
1! = 1
2! = 2 * 1
3! = 3 * 2 * 1
interestingly, 0! = 1
Our Maths teacher was also somewhat taken aback by the prospect of proving something like that. I happened to have already encountered the question when I was in secondary school (junior high), and understood the “secret”: 0! = 1 is true by definition. So I blurted out loud that “it’s by definition”. Maths teacher seemed to agree tentatively: “by definition huh …”
For those mathematically inclined (comprehensible by competent secondary school students):
* Part 2: cold, hard logic
It is the same with God’s existence. For those who are interested in searching for the one true God, God’s existence is true by definition. Here’s how it works in practice:
The word “God” symbolises the highest virtue: God is the Wisdom, Power, etc., that most deserves to be known and worshipped. (Hence also, the statement “God is good” is true by definition.)
René Descartes famously provided a sort of proof for the existence of the self: “I think, therefore I am” (in Latin: “cogito, ergo sum”).
Similarly, Virtue exists because human beings are naturally inclined to have goals and work towards those goals. Virtue determines which goals are more deserving of our attention and effort. Hence the highest virtue (God) dictates the goals most worthy of our worship. Perhaps the foremost virtue is the intellectual humility to acknowledge the existence of higher virtue, followed by the will to seek it:
Proverbs 1:7 New English Translation (NET Bible)
Introduction to the Theme of the Book
Fearing the Lord is the beginning of moral knowledge,
but fools despise wisdom and instruction.
Proverbs 9:10-12 New English Translation (NET Bible)
The beginning of wisdom is to fear the Lord,
and acknowledging the Holy One is understanding.
For because of me your days will be many,
and years will be added to your life.
If you are wise, you are wise to your own advantage,
but if you are a mocker, you alone must bear it.
So God exists by definition because we want to seek God. Interestingly, saying that God exists by definition, simply means that there exists something that fits the set of criteria given by the definition (in this case, “that which deserves to be worshipped”). We do not automatically know what God is like, etc. For example, when faced with a problem, we may be inclined to define that there exists a best solution to that problem. But that doesn’t mean we know what that solution is. We must undertake the potentially long, arduous journey of exploration, continually searching for better solutions, never knowing whether there is a better solution waiting to be found.
Some people are lazy, and settle for what they think is “good enough”. So they stop seeking God, and end up mistakenly worshipping something that is not truly the highest virtue. There is a biblical term for such behaviour: idolatry. (Further reading: https://caveat1ector.wordpress.com/2018/05/28/seek-and-you-will-find/ )
So, the honest, no-bulsh*t version is that God’s existence is true by definition. It is not something meant to be proved. “God”, rightly understood, is something to be found, not proved.
People who are anxious to prove that God exists, are not looking to worship God, i.e. they are not looking to dedicate their lives to some highest virtue. They are simply interested in selling their soul to the highest bidder: the fictitious figure whom “Christians” commonly imagine to be the guy who will pay for their entry into some non-existent after-death amusement park. (Further reading: https://caveat1ector.wordpress.com/2018/05/22/christianity-popular-vs-real-version/ )