The human brain has difficulty comprehending the nature of the Almighty God. After all, the scripture does declare that he is invisible (yet, is seen through things he has made), immortal (yet, came among us in the form of a mortal man) and eternal (yet, he occupies time). One thing that is good for us is that God understands himself and is able to influence our understanding.
1Timothy 1:17 Now unto the King eternal, immortal, invisible, the only wise God, be honour and glory for ever and ever. Amen.”
What the LORD God was in the First Testament he remains in the Second Testament. Jesus is the revelation of the One Mighty God. Perhaps, because of all the doctrines in the world today, this subject is hard for you to understand; it doesn’t have to be if you know the source of understanding.