The babies and children are too young to understand in order to believe.
This does demonstrate fundamental differences on what is meant by the word "faith".
Let's begin small here, with a question:
Can an infant trust his or her mother?
For full disclosure, my goal here is to demonstrate that since an infant is capable of having trust in its mother, that is, to develop a natural faith; then to deny to infants that they can be given supernatural faith, which is the gift of God (Ephesians 2:8) which comes through God's Means (Romans 10:17) is absurd.
Seeing as faith in Christ does not arise through the intellect or by reason, but rather is God's gift entirely apart from ourselves; then to limit faith only to those capable of answering a theology exam
is a denial of grace.
Saving faith, i.e. faith in Jesus Christ, is not an intellectual property or an answer to a theological examination--it is a bold trust in Jesus, the Person Himself, and what He did. And this is not a product of human will and activity, but of divine grace. It is God's work.
Thus when the infant receives God's gifts, that is the Means of Grace, through which God has promised to work to create faith; they receive the same thing you and I have received. For the gift of God is impartial.
Indeed, Christ our God having said, "Do not prohibit the little ones from coming unto Me, for to such as these belongs the kingdom." We do not deny to our children the gifts and grace of God, but welcome our children into our midst as God's People, as the people who hear and receive God's Word, as the baptized disciples of Jesus Christ.
Understanding, growth, maturity--these things come with time. We are all works in progress; we are all being worked upon by God. So, with time, as we rear our children in the faith, they will grow in their knowledge of Christ. Just even as happens with adult converts.
Christ does not discriminate, and God is no respecter of persons. We are all sinners, and as sinners God's love, the love with which He has for the whole world, is for each and every one of us. From the smallest and the weakest, to the greatest. Young and old, male and female, Jew and Greek, rich and poor, slave and free. Tall, short, fat, skinny, black, white, it doesn't matter.
The Gospel is for all.
Christ died for all.
The grace of God is for everyone.
God loves everyone, and desires that all be saved.
-CryptoLutheran