"And in Jesus Christ, His only Son, our Lord..." (Second Article).
By far, the best explanation of the Second Article of the Apostles' Creed is contained in the Small Catechism. It is but one sentence long, but what a sentence!
If I had to add something, it would be this. As the Creed is the center of the Catechism, so the Second Article is the center of the Creed. The heart of the Faith. Christ.
And the rest of the Catechism must be seen in the light of Christ. It is Christ through whom we pray, "Our Father" (Lord's Prayer). It is Christ into whom we are baptized (Sacrament of Holy Baptism). It is Christ in whose stead and by whose command the pastor says, "I forgive you all your sins" (Confession). It is Christ whose true body and blood we eat and drink (Sacrament of the Altar). It is Christ who came and kept the law perfectly FOR US (Ten Commandments).
It is Christ whom the Father has given, and Christ in whom the Holy Spirit gives faith.
Christ is the One who has Won me "from all sins, from death, and from the power of the devil; not with gold or silver, but with His holy, precious blood and with His innocent suffering and death, that I may be His own and live under Him in His kingdom and serve Him...."
Serve Him today as a member of your congregation, as a husband or wife, as a father or mother, as a child, as a worker, as a supervisor, as a teenager, as a widow, as a pastor, as a neighbor to the person in need.
As a Christian, on whose heart are written the words of the Creed.