This question assumes that God-ness is something that all three persons participate in. This is the fallacy. On my view God-ness is not the same thing as divinity. Only one person is God and that is the Father. God-ness is not something abstract as a divine attribute. God-ness is a hypostatic property of the Father alone. The mistake is the way people use the word “God”. Many think it means divinity, or deity. I think, with the Nicene creed that it means origo, auto-theos, source of operation.

Unitarianism [Capital “U”] says that only one person is DIVINE (Nature). Nicene Monarchism (My view-unitariansm [lowercase “u”]) says that only one person is GOD (Hypostasis-Person). The Bible at no point refers to the One God as an abstract essence/subject or nature/subject that attaches to three other relation subjects or the absolute blasphemy of the Tri-Theistic or Monadistic phrase “God the Father, God the Son and God the Holy Ghost”. The only time the NT uses the word “Theos” and attaches a numeric value to it, it is referring to the Father; never to the son or spirit. And the fact remains, the One God is never said to be a divine nature. The Scripture does describe ******the Father****** as the one person who is, “tou monou Theos” (John 5:44 “How can you believe, when you receive [fn]glory from one another and you do not seek the [fn]glory that is from the one and only God?), “ton monon alethinon theon” (John 17:3 “This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent.) and “eis theos” (1Cor 8:6 yet for us there is but one God, the Father, from whom are all things and we exist for Him; and one Lord, Jesus Christ, by whom are all things, and we exist through Him; Eph 4:6 one God and Father of all ).

Some may object: Wait! Didn’t Ryan say, “To be divine is to be eternal, omniscient, good, just, etc. These are universals which may be predicated of the Father, of the Son and of the Spirit; that is, each is divine because there are a set of distinct, divine attributes which may be predicated of each of them.” http://unapologetica.blogspot.com/2012/09/drake-sheltons-triadology-summary.html

Does this not imply that there is a realm of universals higher than the persons? No! Why? Because these universals are Ideas within the mind of the Father. They are the activity of the Father’s being/mind. True, the activity is caused by the being/mind but that in no way implies that the being/mind is caused.  Remember, the Father is the absolute and independent person. He is the only person that possesses these attributes independently. The Son and the Holy Spirit emanate (Christian sense not Plotinian) from the Father eternally, therefore, they possess these attributes in a mode different from the Father, that is derivatively. But doesn’t that mean that the Son and Holy Spirit are different in generic substance from the father? No! Why? Because independency and absoluteness (they mean the same thing) pertains to the hypostasis of the Father, not his nature.

The hypostasis of the Father is therefore the first (logical not necessarily chronological) and highest principle; the One God to whom all peoples owe allegiance, worship and obedience: Shema Yisrael!