Augustine refers to having valued Jesus because of what his mother Monica taught him. He probably admired the person Jesus of Nazareth for being another remarkable teacher or philosopher. I think it would bear resemblance to your average agnostic today.
If you were to take your average lapsed Catholic agnostic, and ask them about Jesus, they would probably be in agreement on many things that perhaps do not agree with the Catholic Tradition. Beyond blaming the sorry catechesis, I think it would be interesting to see the generic and harmless Jesus that can only be the product of an overly materialistic consumer society. Jesus is another self-help guru. I am sure that is how they imagine him. He had some non-religious spiritual wisdom teaching, and he was a healer just like self-help gurus are or whatever. At the same time, there is nothing compelling or urging about this caricature, who can as easily be disregarded with each new pop fad. But by and large, Jesus remains a positive person that even the agnostic has a hard time overtly disrespecting him.
The apostles were vividly struck by this man Jesus of Nazareth. He was like the prophets before him. But he was not like them. He was like the lawgiver before, but Jesus was totally something beyond that. Jesus was, and Jesus was not quite in the way they understood. The Gospel themselves clearly testify to a certain Apophatic reflection on the person of Jesus as they grappled to categorize and bracket him into what their experience knew. Another lawgiver. Another prophet. Another teacher. Another preacher. Another wonder-worker. But Jesus was not any of these things.
Jesus was the son of a carpenter. Yeshua bar Yosef, he would have been referred to. Christ was not his last name (or Joseph and Mary’s). But what was with this guy? He was nothing like his family. There was nothing that could prepare anybody for the authoritative teaching, the inspiring proclamation, and the wonders he worked among the people.
All of this turned them on their head absolutely when they saw him in glory after having been publically executed. Their lives were turned on their head. They all went to the ends of the earth to endure brutal torturous death on account of the proclamation of this wonderful event.
Jesus said that his Spirit would come upon his followers, and there was a concrete and tangible difference. Whereas the Apostles locked themselves away in terror when Jesus was captured, suddenly they had no fear in the face of similarly gruesome torturous assassinations and executions.
They baptized in the name of the Father and the Son and the Holy Spirit. Each of these titles corresponded to something, or someone they experienced. It was clear that Jesus was not the Father that he prayed to, but Jesus was the one with the Father. That Jesus was not the Spirit who came upon the disciples, but there was a unity.
The whole movement of the Church exploded amidst bloody persecutions. There was something alive and flamboyant at work behind the scenes. It took them a while to let their intellectual reflections catch up with their own experience and the tradition. It was clear from the beginning that there were three divine persons, each with their own solid ground and integrity. Yet, It was clear, as has always been that there is still one God.
As the Church Fathers were quite comfortable with articulations about God, balanced with an incomprehensible Divine Mystery, the idea that there God is Triune was not altogether difficult to accept. It is, unfortunately far removed from our experiences. I do believe that the magnitude of the incomprehensibility of Divine Mystery has been so incredibly undervalued publically, that many people do become agnostics. But God has acted in history. God has acted in our lives. It is quite concrete, so much so that it does not make sense to remain an exclusive agnostic for very long. Jesus, the Son of God, had flesh and blood like us. He hungered and feasted as us. And he spoke to us. He speaks to us in the Scriptures. Perhaps the Father is caring, nurturing, and providing for us. Perhaps the Spirit is moving and vivifying us likewise. It does not make sense to remain agnostic, because God is acting in our lives in a concrete manner, demanding a concrete response.
People who remain hard hearted agnostics, often will find themselves deliberated trapped, to protect themselves from hypocritical Christians. They want to see results. They want to see that following God leads to happiness, that the moral life is possible, and that they are all connected. Most of all they are craving communion, not more abstract moral theories, not more abstract moral doctrines. It is not that these have no value.
But the story of God is very personal. The story of Trinity is very personal. The Son of God is Incarnate. The Son of God has eyeballs, ears, a nose, and a tongue. The Son of God has a story, the story is our redemption, the story becomes our story, our story becomes part of his story, our story becomes the Church’s story, the Church’s story becomes our story, the Son of God’s story becomes our story. The Story of God follows with the gift of the Holy Spirit, and we can receive that gift through the Sacraments. We begin our Trinitarian Life at Baptism, in the Name of the Father, and the Son and the Holy Spirit. So it becomes very important for us to be well versed in this story. It becomes important for us to reflect on our personal part in this story in the Life of the Trinity. We see our past with new perspective, and God transforms our pain into something beautiful.
Augustine looked deeply into the story of Jesus, and the story of the Church, and the story of the Communion of the Saints. He saw something too remarkable to deny, and followed his heart into the story.