I don't think the Trinity was invented by Kabbalists, perhaps it's more accurate to say they adapted the concept.
You are correct my friend, but I didn't say they invented it. The Trinity goes way further back than Kabbalah. It goes all the way back to Lemuria, Atlantis, Egypt. It incorporates the truth of how things exist, which is on many different spheres...parallel universes. But Kabbalah is the source of many modern day religious dogmas, esoterically of course. It is the main source of Freemasonry, and many religions are Masonic in nature. A notable one that comes to mind, ironically, is the Jehovah's Witnesses, who were quoted in the article above refuting the Trinity.
Keep in mind though, there are two types of Kabbalah...intuitive and intellectual. They are, respectively, white magic and black magic.