Which mode did you apply?
Scripture attests about two ways one can ascertain JeHaVeH's existence:
1st. - To go alone to a reserved place, like a desert hill or a distant wilderness and call upon the eternal Hebrew name 'I AM THAT I AM' for a response.
2nd. - To ascertain the authenticity of YHWH's words in the prophecies, for example, the fulfillness of the prophecy in the last book of Scripture which gives the instruction to apply accounting for the result 6,6,6. This had been ascertained by math real proofs from counting the number of the beast in a book of 66 books -- a protestant bible.
Both, and then a third. For me, I am convinced of YHWH for three primary reasons.
The first is found within nature, the second is scriptural support coupled, and most importantly is a personal relationship where we have interacted-- which is the most rare, but most fulfilling.
"It is better to shun the bait, than struggle in the snare." -Ravi Zacharias