There is much misunderstanding surrounding the biblical account of God telling Moses, and in turn, Moses telling the Hebrew children that it was "unlawful" to say His name. Many believe and have taught that this has something to do with its "holiness." I don't believe that to be the case. You see, the Hebrew children were just a few generations removed from their father, Abraham, who had come from a pagan society whose religion was polytheistic in nature. For each attribute of the "one God" they had a different name, and interpreted these multiple names to mean there were "many gods." Today, most of the major monotheistic religions understand this. However, then, there was a need for God to impress upon them that He was only one God and that each name they had been taught was simply another aspect of His nature.
Knowing this, I believe God made it unlawful for them to say His name because each of the many names they assigned to his attributes limited Him to that one particular attribute. This is still happening today in Christianity, in a sense because we think we have God all figured out. But when we try to define God or confine God to our limited perspective of Him, at some point, we will run into a theological crisis; have a religious nervous breakdown.
For instance, if we know God and choose to worship God as being only on the side of the poor, our minds become fixed on Jesus' words to the rich young ruler when He says, "It's easier for a camel to pass through the eye of a needle than for a rich man to enter the kingdom of heaven." But the crisis comes when a few days later, Jesus teaches the parable of the talents and declares that if you don't learn how to invest your money so that it makes more money for you, He will take away what little money you have and give it to those who have more than you do.
If you believe that faith is the only way to be justified to God, you'll fall into a crisis when you read in James, "Faith without works is dead." If you believe there is never an appropriate time for war or violence because you have based your entire belief system on Jesus saying to Peter, "If you live by the sword you will die by it," then what do you do when just a few chapters later Jesus tells the disciples to sell everything they have and take the money to buy swords for protection?
If you only know and relate to God as the Alpha, you'll be confused when He shows up as the Omega. If you only know God as male, it's going to mess up your theology when she reveals Her feminine side to you. If you only know God as a Christian, you will be confused when God shows up in and as a Hindu named Gandhi.
The point is, God had to make it clear to the Hebrew children and is still having to make it clear to His children today that we don't have Him all figured out. All we have is our piece of who He has been revealed to us. But in reality, the only true name we should have for Him is "I Am that I Am" - nothing more; nothing less.