Moses said to God, “Suppose I go to the Israelites and say to them, ‘The God of your fathers has sent me to you,’ and they ask me, ‘What is his name?’ Then what shall I tell them?”
God said to Moses, “I am who I am. This is what you are to say to the Israelites: ‘I am has sent me to you.’”
“This is my name forever,
the name you shall call me
from generation to generation.
the name you shall call me
from generation to generation.
-Exodus 3:13-15
God refers to himself as I AM in this passage and The LORD. The word for The Lord here is YHWH sometimes written as Yahweh or Jehovah it is closely related to the Hebrew verb meaning "to be, to exist." This isn't the first time this name is used though. It first appears back in Genesis 2:4.
This is the account of the heavens and the earth when they were created, when the Lord God made the earth and the heavens.
-Genesis 2:4
Now the word for God in the above passage is Elohim, God the Creator, but look at the name that comes before God: LORD. This is the name Jehovah or Yahweh. This name implies a being who is absolutely self-existent. That means He always was, is , and always will be. He doesn't need anyone or anything in order to exist.
He is also the same yesterday, today and forever. Let that sink in. The attributes that make Him God never change, also He is never taken off guard or by surprise. Nothing happens that He isn't aware of. It is a pretty awesome thought that God allows us to have free will, and yet He is already aware of our choices and has planned accordingly, in order to fulfill His will, and He does this on not just a global scale but a universal scale.
When we worship Him we should take time to reflect on this amazing mystery, that as Christians the great I AM is now dwelling in our hearts. He is the hope of glory.