The term "All That Is" is an abstraction.
The term "All That Is", depersonalizes It and makes It an intellectual abstraction. The Divinity is quite personable and interactively supportive of those Beings who are in cognizance of It. Cognizance here meaning some awareness and understanding of It and all that It does and is. Or even better, maintaining a dialogue with it on occasion and treating it as a Companion (because It is). There is an acceptance of You, which is found in involvement with Nature, which is exceedingly rare in encounters with indoctrinated humanity. (Some Native Americans refer to this as "the Companion Energy".)
So, for me, this is a case of immediacy and personal and direct experience, which I find gets lost in such terms as "All That Is", simply because it is more than that, in a direct and personal way.
What you need to comprehend what I am trying to say here, is direct and personal contact with It, at least in some regard, perhaps by encountering Angels, or Avatars, or Devic Beings, just to get the flavor of It. Intimates encounters with Nature. How it FEELS. The emotion of It, the emotions It engenders in you, and all else.
Otherwise, you will never have any direct experience to refer to. The intellect is incapable of comprehending It by analytical means, so the intellect resorts to abstractions. This removes one from the ability to experience It directly and personally. Intimately.
Love is sort of a manifestation of It's intimacy and Oneness, through those Beings who are experiencing Love. Love is an expression and an experience of the Cosmic Harmony, the Divine Beauty, Divine Oneness, the Perfection that exists in all things, despite intellectual judgments based on intellectual appearances. At the core of even the electron, is the flame of Love, the Inner Harmony, which pervades all things. But it is personal and experiencable. Not an bstraction.
One might call Love, a personal taste of Divinity, a blessing of the direct experience of the qualities of the Divine, in ones own life. Like Divinity, Love can be directly experienced, but cannot be analyzed. Why is that? Because real Love (not abstractions of it) and true Divinity (not abstractions of it), are beyond thought. These are conditions of Being, Soul States, an entering of the Transcendent. Simply put, everything that is really worth experiencing is beyond the intellect and cannot be analyzed.
In fact, analysis interferes with any kind of direct experiencing, so when one is investigating Divinity and It's aspects, one must learn to abandon thought, and focus on the immediate and direct experience, granting validity to all experiences, regardless of how mind-bending they might be. People think to darn much. And they forget how to Live. Living does not mean thinking. Living means sensing, experiencing. Life in all forms is Divinity in action. Watch it. Feel it. Get involved with It. Eventually, you will come to treasure It, and you will wonder how you ever got along without It. (Thinking creates a separation from It, because It is not an abstraction, but the Ultimate Reality, and is only directly experiencable.) Reverence for Life is reverence for It. Now, go find out for yourself. Have your own personal experiences. "Merging Vision" is a good start. This is an entry way into the mysteries of the Divine, and into the Miracle Worlds.