It's more than just a belief, it's a foundational principle that underpins everything. Let's dive into what some of our tradition's greatest thinkers have said about it.

We can turn to Maimonides, or the Rambam, as he's more commonly known. In his commentary on the Mishnah, specifically in the chapter called Chelek (which, by the way, deals with who gets a portion in the World to Come), he lays out Thirteen Principles of Faith. These principles, also elaborated on by the Rabbi of Shvilei Emunah, really unpack the core beliefs of Judaism.

The very first principle? Believing that the Creator – blessed be He – exists with complete existence. It's not just that God is, but that He is the source of all existence. Everything that is, is because of Him.

Think about it this way: If we could even imagine God ceasing to exist (and I know, that's a big "if"!), everything else would cease to exist along with Him. But, and this is crucial, if we were to imagine everything else disappearing, God's existence wouldn't be diminished in the slightest. He doesn't need anything else to be! As the Rambam explains, God is abounding. He doesn't need the existence of anything else. Everything else -- intelligences, planetary bodies, everything -- needs Him. This idea, this foundational truth, is hinted at in the very first commandment: "I am the Lord, your God."

But it doesn't stop there. The second principle is about God's unity, His echad (אחד). Now, when we say "one," what do we really mean? Is it like a group of people, all part of the same species? No. Is it like one person, made up of 248 limbs? Definitely not. Is it something constructed, that can be divided into many ones? Nope. Even a simple, unique body that can still be divided isn't quite right. These are all just borrowing the word "one." They're unified in some way, but not truly one.

The true One, the echad emet (אחד אמת), is the unity of the Creator. There’s nothing like it. It's a oneness beyond comprehension, a singularity that defines everything. That's why we proclaim, "Hear O Israel, the Lord is our God, the Lord is One" (Deuteronomy 6:4) – Shema Yisrael, Adonai Eloheinu, Adonai Echad (שְׁמַע יִשְׂרָאֵל, ה' אֱלֹהֵינוּ, ה' אֶחָֽד).

So, what does all this mean for us? It means that our belief in God isn't just a passive acceptance of a higher power. It's an active engagement with the source of all existence, a recognition of the profound unity that underlies everything. It's a call to recognize that everything comes from one source, and maybe, just maybe, that recognition can help us see the world, and each other, with a little more unity, too.