This is directly from the +Diadochos of Photiki quote that Kolo posted in 7447, isn't it? Just to be clear on how proxy fits into all this, are you saying that the child is instilled with literal faith at Baptism, but this faith remains dormant until actual belief, and that the God Parents do NOT somehow awaken that faith in the child, but rather use their own faith (as proxy) for the Baptism?
Our Lord Jesus Christ commands us to baptize in the name of Trinity. There must be a reason for it. He did not specify the age, but simply the manner.
Obviously, there is some difference between those who are baptized and who are not, or else Jesus would not have commanded us to baptize and be baptized.
Through Baptism, we are made acceptable to God. It is a petition for, and a mystery/sacrament of adoption. Clearly, those who have sinned must repent before being adopted. Infants and children have nothing to repent for, so they don't fast or confess, even if they could.
One's adoption must be in a state of being blameless before God. That's all.
There is nothing in it that requires you to stand or to recite, unless you have already sinnerd, which can happen only to adults. In such case, repentance and confession are the only way to present onself, even for a fleeting moment, as blameless before God.
Clearly, for one to wish to repent one must have faith. So faith is indepent of Baptism. You do not get baptized because you have faith; you get baptized because Christ commands it. It's all about God, not about you. It's God adopting you, not you adopting God.
As to whether the infant has a "dormant" faith or not is a ridiculous question. We all have "dormant" faith as God inscribed His laws in our hearts. We are all subject to His laws and we are all capable of righteousness if we cleave to God, in His name.
Some acknowledge them; others don't — just as the thief on the right side of our Lord as opposed to the proud and arrogant fool on His left.
The God Parents, who must be Orthodox, make a solemn promise that they will raise the child in Orthodox Faith. The acknowledgment of faith will be left up to the child when he or she grows up.
We don't let our children grow wild and wait until the "age of reason" for them to go to school. We put them in various educational institutions to learn the ways of life, language, habits, discipline, etc. so they learnt he ways of life on earth.
Likewise, the children are schooled in faith, first by being exposed to praxis and then to participate in it as they mature, so they may learn how to live in faith.
We school our children for this life and for the life to come. That is the orthodox way to raise children. We don't wait until they are "old enough" to wish to go to school.