Son of God - Yet Man
From the Catechism of the Catholic Church, Simplified
How Did Jesus Become Man? (470)
Jesus' "human nature was assumed, not absorbed". Therefore, the Church teaches the full reality of Christ's human body and human soul (with intellect and will). Yet, Christ's human nature belongs to the Son of God. Christ's actions in his human nature derive from "one of the Trinity." Jesus communicates to his human nature his own personal mode of existence in the Trinity. "The Son of God acted with a human will and loved with a human heart" (Second Vatican Council).
Jesus' Human Knowledge (471-472)
The heretic Apollinarius taught that Jesus had no human soul because it was replaced by the Word. Therefore, the Church declared that the Son assumed a rational, human soul which has true human knowledge. This human knowledge is limited and was used in an historical context. Jesus could "increase in wisdom" and could learn from human experiences because he took "the form of a slave" (Phil 2:7).
Knowing God's Plan (473-474)
By union with the Word, Jesus knew what pertains to God, especially in his immediate knowledge of the Father (Mk 14:36) and in his divine penetration into men's secrets (Mk 2:8).
Christ enjoyed a full understanding of the eternal plan, which he came to reveal. He didn't know what he was not sent to reveal (e.g. the time of restoring the Kingdom to Israel) (Acts 1:7).
Having Two Wills (475)
Christ possessed two wills, divine and human. These are not opposed to each other. They cooperate so that the Word made flesh willed humanly all that he had already decided divinely with the Father and the Holy Spirit. Christ's human will "submits to his divine and almighty will" (Third Council of Constantinople).
Seeing God Through Jesus' Body (476-477)
Christ's body, being truly human, was finite. Therefore, his human face can be portrayed in images (Second Council of Nicaea). Through Jesus' body "we see our God made visible and are caught up with love of the God we cannot see" (Christmas Preface). The believer "who venerates the icon, is venerating in it the person depicted" (Second Council of Nicaea).
Importance of the Sacred Heart (478)
"The Son of Man knew me and gave himself for me" (Gal 2:20) Because Jesus loved every person with a human heart, the Sacred Heart of Jesus is rightly considered the chief sign of his love for all human beings. (Pius XII - Encyclical on the Sacred Heart)