I don't personally know anyone like that but they usually end up being some of the most powerful advocates of God and are really good at spreading the Word - our God can withstand scrutiny and does not require us to go on jihad to protect His good name - He's not one of those pitiful Gods...
There are many such life stories out there.
It seems that their militant atheism simply comes from a childish rebellion, though they claim it to be based on “reason”.
However, when they actually engage in the intellectual exercise of investigation into “disproving” God and His Word, they end up finding rationally irrefutable evidence that either it is true, or nothing is true.