A Trinitarian resolution of the paradox of revelation

This post gives a brief summary of some discussion of Karl Barth's approach to the Trinity in Alister McGrath's Theology: The Basics.
The following two claims present a paradox.

1. Humanity is fundamentally incapable of hearing the Word of God, because of the sinful nature of humanity.

2. Nevertheless, humanity has heard the Word of God: humanity is sinful and cannot hear the Word of God.

Barth resolves the paradox in the following Trinitarian manner.

a. God the Father is a revealing God.
b. God the Son is the self-revelation of God.
c. God the Holy Spirit is the means by which Jesus is recognized as the self-revelation of God.

Below is the actual quote of Barth, that McGrath discusses.

The question of the self-revealing God which thus forces itself upon us as the first question cannot, if we follow the witness of Scripture, be separated in any way from the second question: How does it come about, how is it actual, that this God reveals Himself? Nor can it be separated from the third question: What is the result? What does this event do to the man to whom it happens? Conversely the second and third questions cannot possibly be separated from the first. So impossible is any separation here that the answer to any one of the questions, for all the autonomy and distinctiveness it has and must continue to have as the answer to a particular question, is essentially identical with the answer to the other two. God reveals Himself. He reveals Himself through Himself. He reveals Himself. If we really want to understand revelation in terms of its subject, i.e., God, then the first thing we have to realise is that this subject, God, the Revealer, is identical with His act in revelation and also identical with its effect. It is from this fact, which in the first instance we are merely indicating, that we learn we must begin the doctrine of revelation with the doctrine of the triune God.

Karl Barth, Church Dogmatics 1.1 The Doctrine of the Word of God , pages 296-7.