There is a god in Judaism. If you follow Judaism, you must follow a god. Being Jewish doesn't mean you are a follower of the Judaic faith.
I maintain that you're letting the Christian concept of God get to represent all religion's concept of God. God is an exceedingly complex, as well as deep, subject. There's many variations out there. Buddhism has gods. But gods are more facets of human behaviour. You worship the god of silence if your goal is to be silent. That worship and devotion is intended to give you the power and strength to maintain it. The god of silence is the embodiment of silence. The Buddhist gods they perfectly straddle pure symbolism (ie they don't really exist) or magical powers (ie they do exist). The various Buddhist texts keep sliding between these interpretations all the time. It's impossible to know what is meant.
Judaism is a part monotheistic religion (Christianity, Islam) and part Pagan religion. Pagan gods are more along the Buddhist tradition. The gods are embodiments of various phenomena. What makes Judaism special is that it has taken all the various Pagan gods and one-by-one incorporated it into Jehova. This evolution can actually be traced in the Torah itself. It happened over a 500 year period during which time the Torah was written.
Pagan gods don't give a shit whether you believe in them or not. None of the Pagan religions emphasize this. The ONLY thing they care about is that the proper rituals and sacrifices are carried out. As long as you do them, you can go on your merry way, and do what the fuck you like. This is Judaism.
Pagan religion (and Judaism) is based around social control. The Torah and commandments are manuals for life. The important thing isn't that every Jew believes in God, as long as they follow the rules. The Torah even explains this. The Torah is full of all manner of gods. It doesn't deny their existence. It just emphasizes that Jews aren't allowed to worship them. That's what the covenant is about. It's the job of Jews to keep other Jews on the straight and narrow. The Jews are God's chosen people whether they want it or not. You can't control what other people believe. But you can control what they do. This is Judaism.
There's even a song about it in the most Jewish film ever made. And the title of the main theme song explains it all.
https://www.youtube.com/watch?v=gRdfX7ut8gw
That's one of the reasons that Judaism doesn't have confessionals. Jehova doesn't give a rats ass whether you're truly sorry or regret what you did. It doesn't even care whether you let... Moses... into your heart. There's even an awesome scene about it in the beginning of Angels in America. Where the boyfriend comes to the Rabbi and regrets what he has done. The Rabbi answers. "We are Jews. We don't have forgiveness. We have guilt"
Bottom line. A Jew needs to follow the rules because that is what it means to be Jewish. Whether or not God exists is of secondary importance. That is why atheist and theist Jews get on like a house on fire. They don't care that they don't agree on theology.
Judaism (and Paganism) is actually a more civilised religion than Christianity (and Islam). Judaism doesn't have intolerance of other religions built into it's creed.
What does it mean to be "religious"? Are you expanding the scope of the term to cover stuff that is outside the realm of religion? Religions rely on a higher authority for the basis of their moral code. That basis is rarely negotiable.
Moral codes outside of religion and much more adaptable and are not based as much on ancient arbitrary judgements.
I've shown you a list of atheistic religion. Their followers obviously don't agree with your narrow definition of religion. They also don't care about your opinion on the matter. They're religious and atheist and exist. You can obviously pretend they're not there.... if you like. I don't understand your apparent need for denying reality? Isn't that what's wrong with theism?
Moral codes within theist religion are obviously just as open to change as any other moral codes. They had to have been created (by humans) at some point. Right? Obviously God didn't do it. History is full of changes in Christian moral re-interpretation. One of the highest virtues of Christianity used to be to remain chaste your entire life. At some point a Roman Emperor put an end to the worship of Thecla (one of early Christianity's three main saints) and that was the end of that. Since then it was "go forth and multiply". My point is that your idea around the permanence of religious moral codes is ONLY based upon the myth that they are. Most people are conservatives who hate change. That's why they find it attractive to cling to the illusion of eternal morals given to us from God. But they're not. They never have been. Christian morals have been evolving alongside the rest of the society for ever. At no point have Christian morals been static.