טובה שמורה לטובים
Good is kept for the good ones. 
“…What is the greatest possible good that G-d can bestow?…The greatest possible good is G-d Himself. There is no other ultimate true good…The ultimate good is therefore to partake of G-d, and it is this good that He planned to give the world…
G-d therefore created the world in such a way that we could draw close to Him and partake of His essence…Such closeness involves the knowledge and understanding of G-d, as well as resembling Him to the greatest degree possible…
The ultimate good that G-d offers is therefore the opportunity to perceive Him…our sages teach us that G-d created the world in order that men may know Him…
We can therefore say that the ultimate goal of creation is that we should come close to G-d and therefore both know and [revere] Him…” 
The “knowledge of G-d” as a synonym for personal experience is found in the writings of the Rambam (Maimonides).
In other Jewish sources, this “knowledge” is called in Hebrew “Devekut”:
“Knowledge of G-d (called the experience of d’vekut, which means “bonding” or “unifying” in Jewish thought) reveals to me that I and everything else in this temporary world of multiplicity and separation [are] One with G-d. It is seeing, but not with my eyes, and knowing, but [not] through my mind, that duality is not the fundamental truth of existence. That the Infinite and Eternal One is giving birth to creation every single second, and that the flow of history is Divine intelligence unfolding through time. It’s seeing what the kabbalists teach as “Ain Od Milvado,” which…means, “There is nothing [else] than Him.” Judaism teaches that although G-d transcends creation, everything in creation is sourced in G-d; is One.” 
“Devekut” seems very similar to the “Samadhi” of Yoga or the “Nirvana” of Buddhism.
Even so, I’d say that this isn’t the highest step that Judaism promises.
“Devekut” or “Knowledge of G-d” can validly be the experience of an individual. But the promise of Torah, especially as later taught by the N’vi’im (prophets), is that a time will come when the whole world — the whole universe; the whole creation — will be filled with the “knowledge of G-d.”
“In that day G-d will be One and His Name One.” 
That is the world which our hearts eagerly await.
 Sefer Yetzirah 6:4
 Kaplan, Rabbi Aryeh, trans. and ed.; Sefer Yetzirah; Schocken Publications; p. 246-7
 Zacharyahu/Zechariah 14:9