It’s important to remember that they don’t believe this stuff because they are simply stupid, but they have a confirmation bias that many reasonable people would fall victim to.
When you are successful and have the weird version of modesty where you are uncomfortable taking credit for your own work but somehow believe you are a personal beneficiary of “God’s Plan,” your faith will skyrocket.
If you really believe in God and believe you are blessed, you’d be an asshole not praise them loudly and publicly.
I’m an atheist myself, but I don’t think Christians who act this way are being crazy so much as consistent with their beliefs.