I try to not believe things, as a general principle. Why take things as being definitely true when you either have no evidence or the evidence is against them being true? It's not very sensible, really.
Your statement was that we have historical records of the Abrahamic god existing and sending some aspect of himself in mortal form to Earth as his own son.
That is not true. We have historical records of some people believing that as an act of religious faith. That is not the same as a record of it actually happening.
That has nothing to do with whether or not I believe that the Jesus figure existed - your question is an irrelevant distraction from the fact that the statement you made isn't true.
Unless I'm mistaken there is good evidence for the existence of a Jesus figure. This is very relevant as this figure was known as making supernatural claims that he would rise again etc. There is evidence that suggests that the resurrection did happen which according to the Christian faith was the validation of these claims. Of course you don't have to accept the evidence but there does appear to be supporting evidence that may be relevant which needs to be examined.