That you conflate the Gospel with the mystery, even the hidden wisdom does not change the fact that the subject of 1 Cor 2:14 is the mystery, even the hidden wisdom spoken of in 1 Cor 2:7.
1 Corinthians 2:6-8 Howbeit we speak wisdom among them that are perfect [Greek téleios = mature]: yet not the wisdom of this world, nor of the princes of this world, that come to nought: But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory: Which none of the princes of this world knew: for had they known it, they would not have crucified the Lord of glory.
God never hid the Gospel.
2 Timothy 2:15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.
Ephesians 4:14 That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive
You are blown about in your confusion concerning the mystery ... the hidden wisdom which is the subject of 1 Cor 2:14.
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