A person can indeed be filled with the Holy Spirit and not have faith. "Filled with the Holy Spirit" is different from being "indwelt by the Holy Spirit". No one was indwelt by the Holy Spirit until after Jesus was glorified, yet many were filled with the Holy Spirit from the beginning of Scripture, ie: Moses, David, Elisha, Elijah, the Judges, the Prophets, Balaam's donkey, etc.
The fact that John was given the spiritual sense to recognize the Messiah even from the womb does not indicate his mental understanding. Neither he nor even Jesus was not able to understand the Scripture until they learned to speak, and listen to their teachers, and memorized the Scriptures, etc.
As Rom 10 says, how can one have faith if he has not yet believed? And how can one believe if he has not yet heard? etc.
It would appear that it is now incumbant upon you to make the argument that faith is, or requires, a "mental understanding". I'm not aware of that definition of faith in Scripture, but given your confidence in that definition of faith, I'd like to see you back it up.
My position is that faith isn't about a "mental understanding", it's not about the power of the mind, or human reason. Even an infant can have faith. Even those with learning disabillities can have faith. Faith is not a property of higher reasoning, but is a gift from outside of ourselves, given to us, by God, and that it is trust.
The Scriptures consistently point us to the simple, the unlearned, and the child to teach us of faith.
Christ said concerning small children, "To such as these belongs the kingdom" (Matthew 19:14) and also "I thank you, Father, Lord of heaven and earth, that you have hidden these things from the wise and understanding and revealed them to infants;" (Matthew 11:25).
It was the Pharisees and scribes of the law who wanted to glory in their own means of knowledge, and in their own authority, to lord over the common people and who sought to put roadblocks and gatekeep the things of God--but Christ came saying He is the Door and He is the Gate, and all who enter through Him surely enter.
When people brought their little ones to the Savior, some among His disciples tried to shoo them away, but the Lord rebuked them saying, "Do not hinder these little ones from coming to Me".
The Gospel isn't the luxury of the privileged, it is the common and abundant love of the good Father in heaven who so loved the world that He sent His only-begotten Son; and who poured out His Spirit upon all flesh in order that He might bring in many sons and daughters, and that the earth might be filled with the glory of God.
If you want to argue that God denies infants and small children His love and grace (which is what denying them faith
means), then I believe you are going to have to try really, really hard to make a convincing argument.
As for your statement about "nobody was indwelt by the Holy Spirit before Jesus rose", I know that argument, but is there an actual biblical basis for that claim? Or is that just a parroting of a common modern doctrinal refrain? What is the actual, substantive basis for that claim?
-CryptoLutheran