We can see the sun, it's real, doesn't mean we understand everything about it or encompass it completely or even grasps it's full size. In fact, before scientific advance, we had no real estimate of it's size.
Same with the moon.
Doesn't mean we don't know the sun provides heat and light and doesn't mean we don't make use of it's light.
So we see God from a distance as I already explained, we never reach him, but we can see he is endless and absolute in terms of greatness and life amount. Both of these imply he is the necessary being if you realize what necessary means in terms of possible worlds and existence.
For those who don't understand the pigeon hole principle let me draw it for you.
(God's size in terms of existence, absolute infinite )
<-------------------------------------->
<--| | | -----------> (infinite possible worlds)
---p p p (possible worlds)
---|
--- actual world (our world is one of possible worlds)
Now it's true I can't see infinity, but I understand God is Absolute. I can understand infinite possible worlds, and can understand if God is absolute, his existence amount is such that nothing would exist without him.
This doesn't mean we see God completely.
God is seen to be absolute from a distance, be we never get there.
The Sign of God is such that it's a limited circle with infinite points pointing outward towards God. So through his light, though we grasp in in a limited way, we see infinite attributes of perfect and infinite glories of his face, through his face and name is limited, the pointed to is not. Horizontally God has mapped infinite perfections through descent in a created sign from him, through a funnel circle. We perceive both the united glories and lights into the utmost created version which is the holiest light in creation, and we also can perceive that all lights are found in this light.
Yet the light is such that is points to the absolute and returns to it.
Now there is two sides of glorifying God really (can be more, but for sake of what I'm saying):
His Personality
His Size
Sometimes we may say things that attack his personality and hence belittle him in this sense.
But size wise, we can know he can't have an equal or beget or be begotten.
Same reason size wise - we can make use of it, with "possible existence", and know because no possible existence can exist without him by his absolute amount, then by pigeon hole principle he exists.