That is a profoundly honest question, and I wonder if part of what makes it so sharp is that faith, when misunderstood, can indeed look like a surrender of the mind rather than its fulfillment. Yet the tradition I hold dear has always insisted that believing is an act of reason at its very peak, not its abandonment.
St. Anselm of Canterbury, a thinker who wrestled deeply with this very tension between reason and faith, offers a perspective that might reframe the idea of stupidity or weakness. He writes:
"Foolishness says in his heart 'there is no God,' not because the rational mind finds it obvious that God does not exist, but because he is foolish and insipiens... For one thing is to think of the word that signifies a thing, another thing is to understand the thing itself... In the first way, God can be thought not to exist; in the second, by no means. For no one who understands what God is can think that God does not exist, even though he may say these words in his heart... He who truly understands that God is, understands that God exists so truly that He cannot even be thought not to exist. Therefore, Lord our God, You truly exist, and You exist most truly of all" [7].
Anselm is suggesting here that what looks like disbelief is often a matter of engaging only with the word "God" rather than with the reality the word points toward. When the mind truly grasps what is meant by "that than which nothing greater can be conceived," it finds not weakness, but the most solid ground for thought. Far from being stupid, this kind of faith is the mind reaching its proper object — a recognition that there is a Reality so complete that to deny it would be to deny the very foundation of intelligibility.
And regarding the charge of weakness, Santa Teresa of Ávila speaks to the immense strength and transformation that genuine encounter with God brings, distinguishing it sharply from mere imagination or emotional projection. She writes:
"It is clear: since they say he [the enemy] does not understand our thought, much less will he understand something so secret that God does not even entrust it to our thought... Oh great good! A state where this wretched one cannot harm us! Thus the soul remains with such great gains, because God works in it without anyone hindering Him, not even ourselves... It is above all earthly joys and all delights and all contentment... It seems to me that I still do not see you satisfied, because it will seem to you that you could be deceived, that this interior thing is hard to examine... I want to tell you a clear sign by which you cannot be deceived or doubt that it was from God... Always in difficult things, although it seems to me that I understand and speak the truth, I go with this language of 'it seems to me'; because if I am wrong, I am very ready to believe what those with much learning say... At least I believe that whoever does not believe that God can do much more and that He has been pleased and sometimes does communicate it to His creatures, has the door well closed to receiving them" [8].
Teresa is describing something that requires tremendous interior fortitude — a union that transforms the soul from within, producing a peace and strength that no external circumstance can manufacture. This is not the fragility of wishful thinking; it is the strength of being held by a Reality greater than oneself. She also gently reminds us that humility before mystery is not weakness but wisdom — acknowledging that God can do "much more" than our limited categories allow.
I wonder if some of what has been presented to you as "faith" may have fallen short of what these witnesses are actually describing. The Catechism itself acknowledges with painful honesty that "believers can have more than a little to do with the rise of atheism. To the extent that they are careless about their instruction in the faith, or present its teaching falsely, or even fail in their religious, moral, or social life, they must be said to conceal rather than to reveal the true nature of God and of religion" [6]. Sometimes what looks like stupidity in belief is actually a failure of those who were supposed to embody it well.
Perhaps the question isn't whether belief as such is weak, but whether the particular versions of belief you've encountered have been worthy of the name.