Nuh uh. One cannot be "fully God" by any stretch of the grammar or concept, even if its a traditional idea. That's like saying "I am fully Shermana" as if "Shermana" is a type of being rather than a being itself. One can be fully god, as in little g, but the idea of being fully articulated G-d is simply impossible as a concept. Not even G-d would be called "Fully G-d" because there's no such thing as "Fully G-d" in the purely nominative sense. He is fully god of the gods. This is an issue where the meaning of the word "god" gets lost among Trinitarians. It's kind of a "The god" versus "A god" thing in a way.
Jesus has never been G-d, he will never be G-d, and the Trinity and Modalism will always be wrong and deviations from the original intended meanings of the Logos Theology. He has however, always been a god, the Logos, personified Wisdom incarnate, the Highest of the Angels, and the one who was ordained since the foundation of the world to be the Moshiach, the Firstborn of all Created things, the first created and beginning of the Created beings in the Heavens.
First of all, any language about God is necessarily metaphorical -- that is, descriptive but not definitive, for we do not stand outside God in a position to define God. When we speak of Jesus as the Word, what is that word? God! God is embodied in the Word and embodied in Divine Wisdom. It's a metaphor that works and works well, because we are embodied human beings whose experiences are necessarily also embodied experiences. The ancient Hebrews used this metaphor in Exodus, when we are told that God allows Moses a glimpse of the Divine body -- not the face, but the back side. God is not afraid of the flesh, for God found creative expression through flesh. God is known to us only through flesh. Divine wisdom comes to us in flesh, because we are flesh, and God's glory (which Moses asked to see) simply is not available to us except as it is embodied.
God is not afraid of the flesh, but loves it and becomes it.
Second, because we are particular human beings, we understand God's immanence as also particular. Jesus is that particularity in which God is especially present to us -- immanent to us -- embodied to us. Because we're talking metaphor here, I suggest that we need to grow beyond the model of a particular Christ to one that is more universal. God is embodied in the world, and embodied in us, especially, since we are the
imago Dei. We are the part of creation that brings consciousness and sentience to the embodied God. That consciousness is expressed by the metaphor of Jesus of Nazareth.
Third, God as Father, as Son, as Spirit, represents a community metaphor. God created us for relationship. The whole of the bible is about God establishing right relationship with us. Relationship, in terms of human beings, is expressed in community. The Trinity, then, can be seen as a metaphor of the community of loving relationship, and God can be best understood by us, who live, embodied, within communities. We are particular beings, yet, we are also identified and shaped by -- and express ourselves through, communities.
Fourth, the image of God is the essence of our being. We are not sacred because we have been baptized or because we belong to one faith tradition over another. We are sacred because we have been born, and being born -- embodied -- makes us God's image. Christ comes not from far away in first century Palestine, but from the heart of the human soul. We are most deeply divine when we are most deeply human -- as Jesus was deeply human.
John writes, "In the beginning was the Word." He goes on to say that all things have come into being through the Word. The world is spoken into being by God. It comes from the heart of God's Being. Irenaeus speaks of creation coming out of the very "substance" of God. Creation isn't set in motion from afar. The matter of life comes directly from the womb of God's Being.
We share a common ancestry, a common beginning, and a common "heartbeat." In other words, we form a unity in diversity -- like the Trinity. God is the Oneness in which we all share.
This metaphor of One God in three Persons represents for us a wholeness of spirit, matter and energy that defines who we are as human beings, and as the image of God. Jesus, as the quintessential human being -- the completion of creation -- the whole humanity, embodies God in a special way.
Since the stuff of matter emanates from the heart of God, the stuff of matter is God, just as it is also identified as "human" or "rock" or "air." Since, as I mentioned, humanity is uniquely the image of God, and Christ is uniquely human, Christ is also uniquely God, having come body and spirit from God. In that way, Jesus
is fully God, for in what way can he be said to be separate from God? Neither in his embodiment, nor in his particularity.
God is God, because God is One. Jesus is God, because Jesus is particularly One with God, and represents the complete human.