The Holy Spirit works faith in the hearts of sinners and grants forgiveness, life, and salvation through certain means. We call these the means of grace. The means of grace are the word of God and the holy sacraments.
Holy baptism is a sacrament through which the Holy Spirit washes a lost sinner and renews him as a holy child of God. Through baptism, the Spirit forgives sin and grants the gift of saving faith.
The Lord’s Supper is a sacrament through which Jesus Christ gives to his people his true body and his true blood under bread and wine to eat and drink. Through the Supper, the Holy Spirit conveys once again the forgiveness of sins. Through the Supper, the Spirit feeds and strengthens saving faith.