To whom does a Jew pray?

Can He be described? Does He have a name?

No, there is no description with which to imagine Him, no name with which to grasp Him. Even the pronoun “Him” discloses too much to be true—as though He were something that is here or not here, hidden or revealed. As though He were only light.

But He is not light. He is the source of light. At the source of all light, there is no hiddenness or revelation, no being or not being.

There is only “You.” Here, now, known to all beings in Your unknowableness.

As Rabbi Yosef Yitzchak of Lubavitch wrote:

You that all know of You.

You that all put their trust only in You.

You that all plead only to You.

You that no creation nor emanation knows who and what You are.

And so we pray to You alone, for You alone, the Unknowable, are known to all.

Sefer Hakuntreisim Vol. II, pg. 592.