God is everywhere. He is immeasurably vast and yet everywhere he is close at hand, as he himself bears witness:

I am a God close at hand, and not a God who is distant.

It is not a God who is far away that we are seeking, since (if we deserve it) he is within us.

For he lives in us as the soul lives in the body – if only we are healthy limbs of his, if we are dead to sin.

Then indeed he lives within us, he who has said: And I will live in them and walk among them.

If we are worthy for him to be in us then in truth he gives us life, makes us his living limbs.

As St Paul says, In him we live and move and have our being.

Given his indescribable and incomprehensible essence, who will explore the Most High? Who can examine the depths of God?

Who will take pride in knowing the infinite God who fills all things and surrounds all things, who pervades all things and transcends all things…?

The infinite God whom no-one has seen as he is?

Therefore let no-one try to penetrate the secrets of God, what he was, how he was, who he was.

These things cannot be described, examined, explored.

Simply – simply but strongly – believe that God is as God was, that God will be as God has always been, for God cannot be changed.

So who is God? God is the Father, Son, and Holy Spirit, one God.

Do not demand to know more of God….Just as the depths of the sea are invisible to human sight, so the godhead of the Trinity is beyond human sense and understanding.

[…] Therefore, seek the highest knowledge…not with the tongue, gathering arguments from God-free theories, but by faith, which proceeds from purity and simplicity of heart.

If you seek the ineffable by means of argument, it will be further from you than it was before. If you seek it by faith, wisdom will be in her proper place at the gateway to knowledge, and you will see her there, at least in part.

Wisdom is in a certain sense attained when you believe in the invisible without first demanding to understand it.

God must be believed in as he is, that is, as being invisible; even though he can be partly seen by a pure heart.

Columbanus (540-615): Instr. De compunctione, from the Roman Office of Readings for Thursday of the 7th week in Ordinary Time @ Universalis.