If God of Abraham is true, then why didnt he use his intelligent design to make a new

[Aliza]

Did I use the term wrong? Jews don't recognize the attributes of the trinity god that Christians believe, even if a few attributes did come from Judaism. Looking at the description of the Jewish G-d and the Christian god, they do not appear to be the same entity. Jews do not acknowledge radical changes to the definition of G-d, as the Christians have done, so from a Jewish perspective, we are following different entities.

Well technically both faiths should believe in multiple (nonspecific) deities because the same petty jealous creator god acknowledges the existence of others (you'd think it would have been possible to create existence without them)  but is too insecure to share the wealth, and too weak to make a display of annihilating rivals.

I can't speak for Christianity, but Judaism believes what Judaism chooses to believe. You're of course welcome to have an opinion of what we "should" or "or should not" do based on whatever criteria you choose, but Judaism is defined only by what Jews believe.