What Am I?

I am alive
And I have eyes.
I even have a mouth.
But gown, nor dress,
Nor coat have I,
Nor move I north or south.
I’m one of three
But not the greatest one.
A gift that’s free
By God’s decree—
The fount from which I come.
I grow in strength
By preaching of the Word.
Infused and breathed
Inside of thee,
My presence will be heard.
The evidence
Of things not seen,
A knowledge sure and true.
A confidence
God works fully—
The willing and the do.
By me you know
How worlds were framed.
By me the elders gained
A good report,
And promises,
Built arks, hid spies, were slain.
To see of me
A picture view,
Just look outdoors beyond.
A branch ingraft
ed in a vine—
That’s me. I am the bond.
Now one last clue
So there’s no doubt
Your answer is correct;
This central point
Of doctrine stands
to comfort and direct:
By me alone
You’re justified—
But not the reason why.
I’m not the base,
But instrument.
Now tell me, what am I?