The same thing applies to adult baptism, as well. For adults also come to the font without any claim or entitlement. The water with the Word conveys to them the grace of God apart from anything good or bad they have done. The reason the church instructs adults prior to baptism is not to make them deserving of baptism, but to help them know how truly magnificent and mysterious the grace of God is that is bestowed on them in baptism. Lutherans are therefore sometimes accused of not encouraging people to perform good works.
Good works are the fruit that is borne when the fact of salvation connects with people.
But good works are the result of, not the prerequisite for, salvation. By the same token, attending worship, reading the Bible, praying regularly, and helping one's neighbors in the world are all the result of God's grace coming to us. They are not conditions which we must first meet in order to deserve or acquire that grace. A man once died and appeared at the gates of heaven. St. Peter told him that he was welcome to enter, but he needed a thousand points to do so.