Provided the a priori dogmatic assertion that God authored the Bible is correct, which is by no means a proven fact.
Life doesn’t come with guarantees.
I’m willing to bet my life that scripture is ‘God-breathed’, and live accordingly.
There are billions of solar systems, and you want the Creator to be someone you can prove? Someone you can deduce? And what assumptions do you permit?
More to the point, what makes you think you are smart enough to comprehend God?
“Or do you believe just an assumption?”
By definition, assumptions are not proven. It is up to the other side in a discussion to decide if they will agree on the assumption.
Most people who say, “Scripture is true” are using shorthand for “I believe Scripture is true”.
The idea that God is provable is contrary to faith.
Hebrews 11 says, “1 Now faith is the assurance of things hoped for, the conviction of things not seen. 2 For by it the people of old received their commendation. 3 By faith we understand that the universe was created by the word of God, so that what is seen was not made out of things that are visible.”
The word translated faith means:
“1) conviction of the truth of anything, belief; in the NT of a conviction or belief respecting man’s relationship to God and divine things, generally with the included idea of trust and holy fervour born of faith and joined with it
a) relating to God - 1) the conviction that God exists and is the creator and ruler of all things, the provider and bestower of eternal salvation through Christ
b) relating to Christ - 1) a strong and welcome conviction or belief that Jesus is the Messiah, through whom we obtain eternal salvation in the kingdom of God
c) the religious beliefs of Christians
d) belief with the predominate idea of trust (or confidence) whether in God or in Christ, springing from faith in the same”
People regularly say they ‘know’ something, when what they really mean is that they have full confidence in it. If you wish for faith, ask God for it. If you do not wish, then do not ask.