“G-d said, ‘Light: Be’ and Light was…and there were evening and morning, Day One.” 
“…Rabbi Elazar said: ‘[In] the light that the Blessed Holy One created on the first day, Adam saw…from one end of the world to the other’.” 
G-d isn’t an “idea,” although too often spoken of as one. G-d is a reality; in a wider sense, Reality Itself.
G-d is most truly an experience.
“[Sri Ramakrishna said]…what I saw [in meditation] was an infinite shoreless sea of light…However far and in whatever direction I looked, I saw shining waves, one after another…” 
Just like Adam.
The experience can be of Light, but it can take other forms, too: visions, prophecies, poetic inspiration, artistic inspiration (in the example of Bezalel, builder of the Mishkan), a “still, small voice,” and so on.
TaNaCh is a record of the experience of G-d within the world, especially Israel.
We might look at TaNaCh and assume that the experience “ended” with the destruction of the First Temple.
We’d be mistaken.
It continues, even today.
The experience continued within Judaism, but was less clearly recorded. It is also the experience that Christianity and Islam have spread; the experience found in other traditions around the world, too.
We might experience it “suddenly; unexpectedly,” but this is rare. More often, we experience it gradually through prayer, meditation or contemplation.
Even there, though, the experience is only a “first step,” because it ceases when we end our practice, or soon after.
“Normal life” is seeing G-d in the midst of our daily activity.
“Seeing G-d” — not merely “understanding” G-d’s Presence, but perceiving that Light while doing the most mundane things.
Our lives are “Biblical” lives. That is what TaNaCh means to teach us.
 Bereishith/Gen. 1:3, 5
 g’morah to Hagigah, mishnah 2:1, and elsewhere
 Isherwood, Christopher (1980). Ramakrishna and His Disciples. Hollywood, Calif: Vedanta Press; p. 65