Gee, you are so smart, you know more with absolute certainty than any PhD physicist, either that or you lived in a fantasy world. No one with knowledge is certain what to call the source of the Big Bang nor what came before it. Grow up and admit your ignorance.
Like I said your words don't bother me, nor am I uncomfortable about sharing what I was taught.
But I do know this, it is error only that shrinks from inquiry, not truth.
Since you claim you have "knowledge" that no one knows what caused the big bang, then have you ever read the Catholic priest's hypothesis, he said it was the primordial atom from which all things within this world originated from.
But these thing I consider by faith to be immutable , matter can exist without mass, but mass cannot exist without. And mass cannot exist without space even if there is space with mass. And yes, I test the words, whether the be true and I hold fast to those that do.
A person doesn't have to know everything to understand principles, just a little faith, so if somebody had to teach you to read the word of man, who taught you how to read the Word of God? And as Genesis 1:1 illustrates that the answer is one in the same.
If the primordial atom existed before the beginning of time, which didn't begin until it rapidly expanded to form the known and observed universe. so while he claims his hypothesis give you the right to deny God, it will require you to.
While Lemaitre never said specifically what shape the universe was, there is no sense telling you it was spherical

. But if you care crack open your cosmic egg, enjoy...