What does it mean to lack belief in a thing?
"
To believe" is to have assigned truth to a piece of knowledge you posess. Its antithesis, an assigned falsehood, is "
to disbelieve".
Is it possible to lack belief in anything?
Is "lack of belief" to be equated with a "lack of information"?
Is "lack of belief" to be equated with "lacking understanding"?
I think context is important for understanding these questions.
This is because the linguistics of the mind are tricky.
Making a general statement without context can lead to confusion.
A person could lack belief because of lack of information.
A person could also decide that lack of belief is what best describes his position even though he does have a belief and does have information.
Unless you actually attach the contextual elements surrounding a statement, the truth value is not clear.
A lack of belief could be taken as a position in an argument, but psychologically, the mind will tend to resolve the linguistic unknown. When that unknown resolves, a person unconsciously decides what to believe (or disbelieve).
So even if a person claims a lack of belief in something that he has information on and has carefully examined, it is unlikely that he has actually failed to resolve the linguistic unknown within his mind.
For example, a person could say he believes in God, but when asked about statements in the Bible, he will disagree. The truth value of "I believe in God" changes as you add context that modifies the statement.
For example, a person could say he lacks belief in a god, but when you discuss the matter with him and add the context of certainty vs uncertainty to the mix, he will reveal that he actually regards the existence of God to be unlikely and God's non-existence to be likely. The truth value of "I lack a belief (or disbelief) in God" changes as you add context that modifies the statement.
You might ask why a person doesn't simply attach numerous contextual elements from the beginning whenever he makes a statement. The answer is that it's cumbersome to do so. Language often relies on the assumption of invisible contextual elements and the ability of listeners to resolve those invisible contextual elements on their own.