Father Dumitru Staniloae’s theology is Trinitarian. To his understanding Triadology is not just a teaching that originates in Fathers of the Church. It is linked to our personal identification and has its main role for our self-perception and relation with each other. Moreover Triadology “speaks” to us only in the ecclesial communion. The Trinity is the fulfillment of the person in communion. Trinitarian God is seen by Dumitru Staniloae in “social” terms, such as kinonia or communion as the most important constructions of the interpersonal love. In this article the Church is looked upon as reflection of the Trinitarian communion, as an image of the Trinity- an example taken from St. Maximus the Confessor’s ‘Mystagogy’, as well as the Church as mystery of the Trinity. I explore the the Triadology-ecclesiology relation further in the article in the understanding of notions of “person” and “the other.”