As the head of the family should teach it in a simple way to his household

First

What is Baptism?

Baptism is not only plain water, but it is the water set in God’s command and joined to God’s Word.

Which is that word of God?

Christ, our Lord, says in the last chapter of Matthew:

“Go therefore and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit.”
[Matthew 28:19]

Second

What is the gift or benefit of Baptism?

It brings about forgiveness of sins, rescues from death and the devil, and gives eternal salvation to all who believe this, as the words and promises of God declare.

Which are these words and promises of God?

Christ, our Lord, says in the last chapter of Mark:

“Whoever believes and is baptised will be saved, but whoever does not believe will be condemned.”
[Mark 16:16]

Third

How can water do such great things?

Of course it is not the water that does them, but the word of God, which is in and with the water, and the faith that trusts this word of God in the water. For without the word of God the water is just water and no baptism. But with the word of God it is a baptism, that is, a water of life rich in grace, and a washing of new birth by the Holy Spirit, as St. Paul says in Titus chapter three:

“He saved us … by the washing of regeneration and renewal of the Holy Spirit, whom he poured out on us richly through Jesus Christ our Saviour, so that being justified by His grace we might become heirs according to the hope of eternal life. The saying is trustworthy.”
[Titus 3:5–8]

Fourth

What does such baptising with water signify?

It signifies that the old Adam in us should, by daily remorse and repentance, be drowned and die with all sins and evil desires, and that a new person should daily come forth and arise, to live before God in righteousness and purity forever.

Where is this written?

St Paul says in Romans chapter six:

“We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.” [Romans 6:4]

Go deeper with The Large Catechism - Holy Baptism

This translation is by the Evangelical Lutheran Church of England (2016). Distributed under Creative Commons Licence CC BY-SA 4.0 (Attribution-ShareAlike 4.0 International)