Mary was found with child of the Holy Ghost, whom Jesus called his Father. Can two, father one?    Of Course not.  Therefore the Father and the Holy Ghost are one, and have the same name.  The same as the Son and the Father. (Mathew: 1::18)
Again, God is
ONE, not three in one, but ONE. (1 John 5:7)  See also: Deut: 6:4: Hear, O Israel: The LORD our God is one LORD: Isaiah: 45:5, 45:6, 45:18, 1 King 8:60.  He is also called the Holy One of Israel.
The Lord spoke of Himself in the singular form, whether he used the word (Jehovah, i.e. Yahweh, YHWH, or Elohim (God)- which is a word in the plural form, God referred to himself as ONE.) When the voice from heaven spoke of Jesus, He said, I am IN him.  (In whom I am well pleased.) God in Christ reconciling the world to Himself.  Here, God is Christ, or Christ is God.
Some believe that this name means that God is more than one somehow, but God is greater than the English or Hebrew languages, so in order to describe Him, therefore, he is expressed in these terms. in the word of God also, such as Acts 28:3, etc.
Here is an explanation from a Jewish Lindquist who is an authority on the Hebrew language: 

  • The Hebrew word elohiym, commonly translated as "God" in most modern translations is a masculine plural word meaning "powers".  The word used  in (Genesis) 1:1 as the subject of the verb "bara" meaning He fattened where the He  identifies the subject of the verb as a a masculine singular.  Because of the  conflict of number where the verb identifies the subject as singular, but the subject being a plural word, it is apparent that the word "elohiym" is a proper name and not a noun and is  therefore translated as "Elohiym (powers).--Jeff Brenner, founder of the Ancient Hebrew Research Center.

Here we have established the Father, Son and Holy Ghost are One, as stated in 1John 5:7.  The fulness of God is in Jesus Christ.  Therefore being one, there is only one name that was heraled by the apostle Peter, the holder of the keys to the kingdom of God.  Because God is one, he has one name. 
1John:5:7: For there are three that bear record in