All of what we can observe of reality shows order and predictability. It shows something which can be described as "Certainty".
Certainty requires God.
If there was no God, reality would be disorderly and unpredictable. Objects would fall up instead of down whimsically. Water would boil and freeze nobody knows when or how.
It's also funny to me how all of the answers of Atheists mention God endorsing the commission of immoral acts. If there is no God, how can you call an act immoral? Why is genocide, rape or slavery wrong? If there is no morality, genocide, rape and slavery just are, and cannot be wrong or right. Right and wrong just don't exist.
Morality requires God. If there is no God, no acts are better or worse than other acts. All are just acts.
I'm unaffiliated because there is no reason to suppose any one single religion contains the majority of the truth. It would be, actually, very much at odds with the limitations of human intellect if any one were.
On the other hand, most religions seem to contain an inordinate portion of essential truths which cannot be explained away. Revelation is "too true" to just be arbitrary and a matter of taste.
Theologically, I agree with the principles and tenets of Calvinism; such as predestination, the fallen character of human nature and salvation by Grace. But I'm theologically diverse because, again, it would seem impossible for any one religion to arrive at the majority of the truth. I coincide greatly with parts of Shiite Islam, Shaivite Hinduism (but also with Vedic Orthodoxy), Theravada Buddhism, small Christian movements ancient (Montanism), historic (medieval heresies) and modern (Christian Science, Children of God), small new religions (Raelians, Thelema), and Pagan traditions (Kurdish, Hellenic). I even regard ad hoc religions (Pastafarianism, Kopimi) and fictional religions (Jedi and Sith, Lovecraft cults) as equally true to "real" religions, in the same way that Esperanto, Tolkien Elvish and Klingon are as real languages as English, Chinese, Haitian Creole or Etruscan. Even my Christianity is heterodox, because I'm a modern Docetist: I deny the historical existence of Jesus, without denying the divine inspiration of the NT.
So, I'm unaffiliated; reluctant to fully affiliate anywhere, but also a little reluctant to fully disavow any religion in whole.
At the same time, I'm very, very religious.
I don't see any contradiction between these two stances.
But, if you wanted a short answer, I'm a Calvinist. Who forms a one man church.