Paul may have intended a "double entendre":
A double entendre (/ɒ̃ˈtɒ̃d(rə)/; French: [dubl ɑ̃.tɑ̃dʁ(ə)]) is a figure of speech or a particular way of wording that is devised to be understood in two ways, having a double meaning. Typically one of the meanings is obvious, given the context, whereas the other may require more thought. The innuendo may convey a message that would be socially awkward, sexually suggestive, or offensive to state directly (the Oxford English Dictionary describes a double entendre as being used to "convey an indelicate meaning", whilst Longman Dictionary of Contemporary English defines it as "a word or phrase that may be understood in two different ways, one of which is often sexual").1
A double entendre may exploit puns to convey the second meaning. Double entendres generally rely on multiple meanings of words, or different interpretations of the same primary meaning. They often exploit ambiguity and may be used to introduce it deliberately in a text. Sometimes a homophone (i.e., another word which sounds the same) can be used as a pun. When three or more meanings have been constructed, this is known as a "triple entendre", etc.
This is because the word translated "fools" seems to refer to one who is ignorant of God's ways and also to have the sense of "unsophisticated and unimpressive":
- Ignorant of (or blinded to) God's ways:
[Mat 23:17 KJV] (17) Ye fools and blind: for whether is greater, the gold, or the temple that sanctifieth the gold?
- It also has the sense of "mentally challenged":
[Pro 26:12 NKJV] (12) Do you see a man wise in his own eyes? There is more hope for a fool than for him.
<[Pro 29:20 NKJV] (20) Do you see a man hasty in his words? There is more hope for a fool than for him.
- Unsophisticated and unimpressive:
[1Co 1:27 KJV] (27) But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty;
So when he says "we are fools" he does not mean that the apostles are blind, ignorant or mentally challenged but rather that unlike the eloquent celebrity preachers of Corinth, Paul's speech is devoid of all artifice and reduced to the simple and uncomplicated speech of one a ploughboy:
[2Co 3:12 KJV] (12) Seeing then that we have such hope, we use great plainness of speech:
Some saw in Paul's lack of Roman rhetorical and Jewish rabbinic trappings in his writings were fodder for his opponents whose vain philosophy dominated Rome and Judah. But Paul was jealous lest his "children" wander from the simple truth into satan's realm of the principles and reasonings of men:
[2Co 1:12 KJV] (12) For our rejoicing is this, the testimony of our conscience, that in simplicity and godly sincerity, not with fleshly wisdom, but by the grace of God, we have had our conversation in the world, and more abundantly to you-ward.
[2Co 11:3 KJV] (3) But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ.
All of God's proper theology is found only in one repository:
[Col 1:25-29 NLT] (25) God has given me the responsibility of serving his church by proclaiming his entire message to you. (26) This message was kept secret for centuries and generations past, but now it has been revealed to God's people. (27) For God wanted them to know that the riches and glory of Christ are for you Gentiles, too. And this is the secret: Christ lives in you. This gives you assurance of sharing his glory. (28) So we tell others about Christ, warning everyone and teaching everyone with all the wisdom God has given us. We want to present them to God, perfect in their relationship to Christ. (29) That's why I work and struggle so hard, depending on Christ's mighty power that works within me.
[Col 2:3-4 KJV] (3) In whom are hid all the treasures of wisdom and knowledge. (4) And this I say, lest any man should beguile you with enticing words.
The power is in the gospel, not in philosophy about "universal Church", "same substance", "Trinity", "hupostases", monophysites, etc. Paul determined to know one thing and that was Christ crucified:
[1Co 2:2 KJV] (2) For I determined not to know any thing among you, save Jesus Christ, and him crucified.
Paul became a fool - ignorant of all philosophy and rhetoric - to preserve for the Corinthians that which can make them truly wise.
And he told the Corinthians that if they wanted to become wise, they too should abandon their ambition to peer into profound mysteries and ponder with him what it means to be in Christ as he is murdered for our sins and rises again, and to be found in him at his soon return.