In this article, the author ponders about an absence of treatises on God's attributes in modern monographs about God trinus and unus. The unquestionable importance of this area of theological reflection is connected with several problems that the author tries to solve for the present time. Firstly, it is necessary to prefer the way of negative theology, and we should be aware of God always transcending the being we think. The intellectual cipher in this world of the mystery of the living God is a paradoxicalness that we do not have to be afraid of. Secondly, we need to connect ontological utterances with the history of salvation, which is possible if we see them on the basis of the structures of systematic Christology as a point of the drama of revelation and salvation. The new ontotheology must not be used as something that precedes the experience of faith, but as a moment of intelligibility of mystery implicit to faith. As a consequence of it, the new ontotheology will be implicit, not only to faith and historicity, but also to spirituality. On the basis of confrontation with the biblical faith, the author traces a paradoxical polarisation necessity/freedom, which allows him to enter the area of Trinitarian ontology, as the immanent Trinity asserts a perfect mutual penetration of freedom and necessity: God is such as He wants to be, and He wants to be as He is. The given solutions have their importance mostly for the methodological field, and several given proposals call for a subsequent study, where the traced principles will be applied together with the principle of paradoxicalness in the presentation of individual attributes of God trinus and unus.