If we are to interpret questions about the mental state of a fictional character as being about the intent of the author, then in this case the answer is surely no – as the authors of the gospels clearly did intend readers to believe in the divinity of their subject.
But when it comes to whatever real person or person those stories are based on, the idea that they were delusional is plausible – even if we admire the delusion to the extent of calling it a “divine madness”. Though on the other hand, it is also possible that a sane person might choose to claim godhead without actually believing in it for the purpose of achieving some political or social goal.
Source: Neale’s blog