Quite the opposite actually. Most persons who become atheists do not understand the religions that they have left. They might understand them on a superficial, outward level, but leave too much to the priests and externalities. The superficial does not satisfy and they cannot penetrate it to get to the substance. This is especially true in Catholicism, where so many ex-Catholics have a view of religion that is entirely legalistic.
Sorry but belief (including faith) and knowing or understanding are not the same things.
You are genealising that atheists, as in ex-theists, being ignorant. But how do you know.
Belief don't mean intelligence or being logical or rational. Belief don't require intelligence. The only thing belief required is conviction, thus FAITH.
FAITH is the exact opposite of intelligence.
I have met a lot of theists here, some are indeed, very intelligent than others, but not all of them are very bright. Most of them (the not so bright ones) often resort all sort of logical fallacies (circular reasoning, confirmation bias, argument from ignorance, appeal to authority, no truth Scotsman, wishful thinking, god of the gap, etc) and I find those who called labelled themselves "creationists" to be far from honest.
To give you an example. I find that many of the Christians who believe in the virgin birth, miraculous as they may be, would often believe in the (anonymous) author to the Matthew gospel, of Isaiah's sign. (sources: Matthew 1:22-23 cf Isaiah 7:14)
I had recent argument with Deeje on this matter, in another thread.
For me, I used to believe in this sign being a prophecy of Jesus' virgin birth, but 20 years after I have 1st read these verses time, I have reexamine it, and found the gospel's claim to be untrue.
If you read only Matthew's verses by itself, then sure, Christians will think that it is true. But if you go back and re-read the entire chapter of Isaiah 7, you would see that the gospel writer have left something out, the other things it say about the child Immanuel, and none of it had anything to do with the virgin birth or with the messiah.
The sign was given to Ahaz, by Isaiah, as a sign when the war with Pekah of Israel and Rezin of Aram will end with Assyria's intervention. The Assyrian intervention will occur WHEN the boy (Immanuel) reach a certain age.
So clearly the sign have to do with the war in the 8th century BCE, and nothing to with virgin birth and the messiah.
If Christians were honest people, then they should read the WHOLE CHAPTER, and not just as the gospel author did in Matthew 1:22-23.
The gospel author took Isaiah's sign out-of-context, because he had ignored the 3 crucial verses that followed 7:14, relating to Immanuel:
Isaiah 7:14-17 said:
14 Therefore the Lord himself will give you a sign. Look, the young woman is with child and shall bear a son, and shall name him Immanuel. 15 He shall eat curds and honey by the time he knows how to refuse the evil and choose the good. 16 For before the child knows how to refuse the evil and choose the good, the land before whose two kings you are in dread will be deserted. 17 The Lord will bring on you and on your people and on your ancestral house such days as have not come since the day that Ephraim departed from Judah—the king of Assyria.”
The "child" in 7:16 and "he" in 7:15 are all Immanuel.
Since Jesus didn't fulfill any of the sign in verses 15, 16 and 17, then Jesus isn't Immanuel.
The sign of the event is not the birth of boy named Immanuel; no, the EVENT of the sign is when the King of Assyria take the wealth (spoils of war) from the lands (thus Israel and Aram) of the two kings (Pekah and Rezin), WHEN Immanuel reach the age of being able to eat curds and honey, and the age when he know the differences between good and evil. Clearly, this isn't Jesus.
The sign of Immanuel relating to the war (and to Assyria), is further confirmed when he mentioned again in Isaiah 8:1-10, in verse 8 "O Immanuel" and in verse 10 "God is with us".
Isaiah 8:5-10 said:
5 The Lord spoke to me again: 6 Because this people has refused the waters of Shiloah that flow gently, and melt in fear before Rezin and the son of Remaliah; 7 therefore, the Lord is bringing up against it the mighty flood waters of the River, the king of Assyria and all his glory; it will rise above all its channels and overflow all its banks; 8 it will sweep on into Judah as a flood, and, pouring over, it will reach up to the neck; and its outspread wings will fill the breadth of your land, O Immanuel.
9 Band together, you peoples, and be dismayed;
listen, all you far countries;
gird yourselves and be dismayed;
gird yourselves and be dismayed!
10 Take counsel together, but it shall be brought to naught;
speak a word, but it will not stand,
for God is with us.
It is apparent, that the sign 7:14-17 and 8:3-4, are similar, which would indicate that Immanuel of Isaiah 7 is really Isaiah's son, Maher-shalal-hash-baz. So the al-mah "the young woman" in 7:14 is actually Isaiah's unnamed wife - "the prophetess" of 8:3.
Isaiah 8:1-4 said:
8 Then the Lord said to me, Take a large tablet and write on it in common characters, “Belonging to Maher-shalal-hash-baz,” 2 and have it attested for me by reliable witnesses, the priest Uriah and Zechariah son of Jeberechiah. 3 And I went to the prophetess, and she conceived and bore a son. Then the Lord said to me, Name him Maher-shalal-hash-baz; 4 for before the child knows how to call “My father” or “My mother,” the wealth of Damascus and the spoil of Samaria will be carried away by the king of Assyria.
If Christians were truly honest, then they should know that the gospel author was cherry-pick Isaiah's sign, and taking the original sign out-of-context.
This is coming from understanding the verses, but a lot of Christians take gospel over what Isaiah 7 & 8 are actually saying, which is cherry-picking what they choose to believe to actually understanding the verses.
The problem is Christians have the tendencies to allow their belief to cloud their judgement when interpreting prophecies or signs in the Old Testament. It is called "biases", not understanding of the holy text.
BTW, I am agnostic, not atheist. In the last 18 years, I have been trying to understand the bible, OT & NT as they are, and have been trying to not use Christian preconception on non-Christian books. The Book of Isaiah isn't a Christian book, so it shouldn't be treated as prophecies of Jesus.
And I think most Jews would agree with my interpretations of Isaiah's sign, even though I am not Jewish.