Note that the relations of the three persons of the Trinity never imply the dissolution of the individual person. That the persons of the Trinity mutually indwell each other never means that they become each other. It means that, eternally, completely, they are together. They breathe each other, and dance with each other, but do not collapse into each other. Likewise, our ability to be individuals (made in and for relationship) comes from our being made in the image of God.
How can we express the relationship given to us by being made in the image of God? By loving, first God and then neighbor. Why does that gift of love–for love is a self-donation, self-giving–not result in the loss of ourselves (if done wisely)? It is because loving another is the way that we become the persons that we were meant to be.
According to the Eastern Orthodox understanding of the Trinity, this mutual inherence is the expression of the monarchy of the Father. There is a relation of asymmetry in that the Son and Spirit have a relation of origin with the Father, but what that relation of origin indicates is that Father, Son, and Holy Spirit mutually inhere in each other and mutually define each other. God is God irrespective of creation, but that the Father is Father necessarily includes the Son (and vise versa). “For those who want to save their life will lose it, and those who lose their life for my sake will find it” (Mt. 16:25); this is not merely a text that applies to the created economy. Christ crucified reveals this salvific dynamic to us as the eternal life of God. It is both our salvation and our true humanity to participate in this life, just as it is the Son’s eternal being to give his life away. And, the Son, exactly reveals the Father; by Christ’s dying for us, he showed us what it means that God himself is truly alive.
The life of the open hand (not clenched fist, holding onto what is ours), is the life in which we become true selves, true persons. It is the image of God who forever is self-transcendent, who forever gives, whose life is the mutual in dwelling of the Trinity…
What is the image of God? Love God with all you are, and love your neighbor as yourself.
~Steven Cone, Theology From the Great Tradition, Module VI: Human Beings