need help with lyrics

hi guyz earlier this morning I've been listening to the song stay by 12 stones. I think in this song he's asking God to stay in his life because he cannot live in this world alone, but there's a line in the song that seemed out of place.
"you never know, you never know tomorrow, don't walk away"
didn't God already know our future from the start? I'm confused. Or maybe I'm interpretting this the wrong way. Any ideas or other meaning?

I don't think I have heard this song so can't say, but maybe someone else here has. Which album is it on?

Seems like it could be interpreted either way. About an unsure believer, or about a guy and girl.

LYRICS:

I walk to the edge again, searching for the truth
Taken by the memories of all that I've been through
If I could hear your voice then I might be
Okay
I know that I've been wrong but I'm begging you
To stay. Won't you stay?

Will you be here or will I be alone?
Will I be scared? You'll teach me how to be strong
And if I fall down will you help me carry on?
I cannot do this alone.

I wish that I could turn back time just to have
One more chance to be the man I need to be.
I pray you'll understand.
If I could hear your voice I might be okay.
I know that I've been wrong but I'm begging you to stay.
Won't you stay?

I need your hand to help me make it through
Again
Nothing compares to how I feel when I look at
You
You never know, you never know tomorrow
You never know, you never know tomorrow, don't
Walk away

I am not alone I know you're there.