Jesus Christ, true God and true man, in the unity of the divine Person
This great mystery, that Christ is Head and Lord of all things, has been “manifested in the body” to men and women. The man Jesus Christ, who lived among men and women, labouring with his hands, thinking with a human mind, acting with a human will, loving with a human heart, is truly the Word and Son of God, who in a sense joined himself to every man and woman through his incarnation (see GS 22).
Catechesis must preath Jesus in his concrete existence and in his message: it must, that is to say, give people such access to the wonderful perfection of his humanity that they will be able to acknowledge the mystery of his divinity. In fact, even though Christ Jesus was joined to the Father in an assiduous and unique habit of prayer, he lived in closest contact with men and women. His goodness embraced all, the just and sinners, the poor and the rich, fellow-citizens and foreigners. If he loved any people more than the rest, it was the sick, the poor and the lowly. He showed a reverence and a solicitude for the human person which nobody had ever shown before.
Catechesis must constantly defend and strengthen belief in the divinity of Jesus Christ, so that he may be accepted not only for his admirable human life, but will be acknowledged from his words and signs as God’s only Son (see John 1:18): “God from God, light from light, true God from true God, begotten not made, consubstantial with the Father” (DS 150) The right understanding of the mystery of the incarnation has developed in Christian tradition: Fathers and councils directed their efforts, by constant study of the faith, towards refining the concepts, towards explaining more deeply the exact nature of the mystery of Christ, towards investigating the mysterious links between him and the heavenly Father and the human race. There is the witness to this truth which the Church has provided through the ages, the witness of the Christian life: the communion between God and human beings which is given in Christ is a source of joy and unbounded hope. The fullness of divinity is in Christ, God’s love for the human race is made manifest in him.
Saint Ignatius of Antioch has written: “There is but one physician, bodily and spiritual, born and unborn, God in flesh, true life in death, from Mary and from God, at first incapable of suffering and then capable of suffering, Jesus Christ our Lord.” (Enchiridjon patristicum, 39)