When a person has preserved their baptismal innocence, belief in God and His Holy Law comes easy. When a person stains his innocence, and makes a pact with sin, this easy, fluid understand and acceptance of God starts to gradually fade.
In this first stage of innocence in our soul, our reasoning has a rectitude and natural certainty. Our first certainties resemble, for example, the candor with which we hug our mother when afraid of danger.
We do not reason it through and think: “This lady is stronger than me. I am weak. Therefore, I need her protection.”
We act out of a non-reflective spontaneity. We consider reflection superfluous because such is the clarity of the first data of reality that we possesses, that a careful exam becomes unnecessary.
Our first reasoning is so fluent, limpid and methodic that the question of method does not even arise. It is a kind of transparency.
Imagine a very innocent boy placed next to a river in which there are some rocks. The water runs over the rocks, there are shadows, the sun shines a bit. At a certain moment he may think:
“Why do I think? What is thought?”
And he soon comes up with an answer which, as it were, rose from the evidence like vapor. So, when his mother tells him that God exists, he naturally accepts and exclaims: “Ah! that something that explains everything, is God! It’s true!”
He was not lectured on St. Thomas Aquinas’ five proofs of the existence of God; but later on, when he learned about them, it was like something he had already known and seen: all that was missing was to make it explicit.
As a development of his innocence, the child has an implicit notion of the existence of God. ‘A gushing, tremendous, luminous notion.’
Then one tells him that Jesus Christ came to the world. One tells him about the Child Jesus. The boy believes in the Child Jesus.
It is because everything matches so well with what is on his mind that, for example, he does not even think about asking why the Child Jesus was born and whether it can be proved. The boy deems it so natural for Him to have been born that he needs no proofs.
However, when innocence is shattered through sin, this limpid vision of things is shattered as well.
And by innocence, we understand that first form of alliance that we all had with God in our first childhood. It is a grace of the pristine times in which God was pleased to converse with us, his creature.
But when one breaks this alliance by sin, the natural consequence is to try to justify this sin by denying the existence of God, the author of Law and morality.
This is the real reason why when a person has stepped on their baptismal innocence, belief in God and His Holy Law becomes so difficult. When a person stains his innocence, and makes a pact with sin, this easy, fluid understand and acceptance of God fades.