One day, as he was teaching the people in the temple and preaching the gospel, the chief priests and the scribes with the elders came up and said to him, “Tell us by what authority you do these things, or who it is that gave you this authority.” He answered them, “I also will ask you a question; now tell me, Was the baptism of John from heaven or from men?” And they discussed it with one another, saying, “If we say, ‘From heaven,’ he will say, ‘Why did you not believe him?’ But if we say, ‘From men,’ all the people will stone us; for they are convinced that John was a prophet.” So they answered that they did not know whence it was. And Jesus said to them, “Neither will I tell you by what authority I do these things.” Luke 20:1–8 (RSV)
'I do not seek to understand so that I can believe, but I believe so that I may understand; and what is more, I believe that unless I do believe, I shall not understand. Amen' St. Anselm 1033-1109
A newborn on the day of their baptism is a believer in the death and resurrection of our Lord. It is a mistake to say that one must first come to some understanding of God, then seek baptism. It would make more sense to demand that an infant explain the nature of the universe before it could be fed.
The root sin of humans lies in the desire to be God, know what God knows, to place ourselves on His throne. When our first parents rebelled against God, reaching for the knowledge they could not bear, they chose to trust themselves over God.
Faith is never merely a matter of knowledge of the ways of God. These things lie beyond us, we cannot but fail if we seek God in this way. St. Anselm saw clearly that without faith, we cannot begin to understand the least thing of the Divine nature.
In faith, we are drawn into the mystery that is the love and purpose of the Holy Trinity. We can pray, 'Thy will be done,' in great joy, believing that will is all as it should be. This will sustain us for this life, until we shall see Him face to face. Then we will finally know the perfection of His will and purpose.