This has to do with Sola Scriptura, and you already commented on it to object to my conclusion.
You just evaded. Any normal honest child would answer the question. You are an unbeliever in Scripture and in the God of Scripture. Like the Jews of Jesus' day, you have your own religion according to your own traditions, not according to Scripture.
And Jesus answered and said unto them, I will also ask of you one question, and answer me, and I will tell you by what authority I do these things. The baptism of John, was it from heaven, or of men? answer me. And they reasoned with themselves, saying, If we shall say, From heaven; he will say, Why then did ye not believe him? But if we shall say, Of men; they feared the people: for all men counted John, that he was a prophet indeed. And they answered and said unto Jesus, We cannot tell. And Jesus answering saith unto them, Neither do I tell you by what authority I do these things.
You reason with yourself, that if you say yes, then you also know anything that is not provable by Scripture cannot be declared as true of God, and if anything contradicts Scripture, it must be false.
Which of course is Sola Scriptura. Which is why your answer is "I won't tell".
You reject Sola Scriptura because you reject all Scripture as true of God.
You are an unbeliever.
(You are to be commended however for not allowing yourself to lie about believing all Scripture of God. Though, you did so in a childish little way, because you are not a little child coming to Jesus and His Word, written as Scripture of God)