One God: One Divine Nature and Being
What the Father is, the Son and the Spirit are also. This is the Church’s teaching. The Son, born of the Father, and the Spirit, proceeding from Him, share the divine nature with God, being “of one essence” with Him.
Thus, as the Father is “ineffable, inconceivable, invisible, incomprehensible, ever-existing and eternally the same” (Divine Liturgy of St. John Chrysostom), so the Son and the Spirit are exactly the same. Every attribute of divinity which belongs to God the Father—life, love, wisdom, truth, blessedness, holiness, power, purity, joy—belongs equally as well to the Son and the Holy Spirit. The being, nature, essence, existence and life of God the Father, the Son and the Holy Spirit are absolutely and identically one and the same.