Apparently you do not understand the Mystery of the Gospel of Christ.
I will try to help you with that, and, once you do understand this Biblical Doctrine a little better, you may need to edit some of your postings.
Perhaps it is YOU that need to understand that the Mystery was not the Gospel, but the Gospel being delivered to the gentile nations. There was no "mystery" hidden from the prophets concerning the death, burial, and resurrection of Christ. Or there would be no prophetic statement of such to be fulfilled.
No the mystery of the Gospel was that the Gospel was to be taken primarily by the Gentiles to the Gentiles, and that the Jews as a group would be for a time inattentive.
I have already given two passages, and I do not even see you give them any consideration, so, I will give them again and ask you to address my comments and to show why they do not show that the Gospel was a Mystery not revealed to men in Ages past:
Romans 16:24-26
King James Version (KJV)
24 The grace of our Lord Jesus Christ be with you all. Amen.
25 Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,
26 But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith:
...Where it is made clear that the Gospel and the preaching of Jesus Christ by Paul...
...was according to the revelation of the Mystery which was kept secret since the world began.
Why would you then go on to say it was known to men?
In what OT passage does it state that the Gentiles were to be the bearers of the Gospel and not the Jews?
In what OT passage does it make prophetic statements of the gospel being carried and preached to every nation?
Was not the birth foretold in the prophets?
Was not the death foretold in the prophets?
Was not the resurrection foretold in the prophets?
Was not the return foretold in the prophets?
What part of the Gospel (the good news) was not foretold by the prophets?
There was no mystery in the Gospel message, but the mystery of the gospel was were and to whom that message was going to be delivered.
Not a single prophetic statement that I can find addresses the issue that the gospel would be delivered to, carried by, and held in esteem by Gentiles rather then the Jews.
Vs 26 of the above post shows support for what I am holding, and disproves your thinking.
This next one...
Ephesians 3
King James Version (KJV)
1 For this cause I Paul, the prisoner of Jesus Christ for you Gentiles,
2 If ye have heard of the dispensation of the grace of God which is given me to you-ward:
3 How that by revelation he made known unto me the mystery; (as I wrote afore in few words,
4 Whereby, when ye read, ye may understand my knowledge in the mystery of Christ)
5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
...also makes it clear that it was by revelation that the Mystery of Christ was revealed to Paul.
It is also clear...it was not made known in other Ages to the sons of men. That is all inclusive of all men in all time prior to the revelation of the Mystery.
It was made known by the Spirit, which when we balance God's Word, is none other than the Comforter.
Now, tell me how it is that God's Word can teach that the Gospel of Christ was not revealed to men in past Ages, and by what authority you make null and void two very clear passages about the teaching of the Mystery of the Gospel.
Then we will proceed to our next passage which shows the Gospel was not revealed to men in past Ages.
And just so you know, I am not saying, nor is Scripture, that the Gospel is not found in the Old Testament. What I am saying, as is Scripture...
...is that understanding of it was not given.
I am not going to respond to your posts unless you do me the same courtesy, so address this post.
God bless.
OK look carefully at Ephesians again, for Paul states EXACTLY what the mystery he is talking about actually is.
Here again is the opening of Ephesians 3 with a bold part showing what the mystery actually is that Paul states:
1For this reason I, Paul, the prisoner of Christ Jesus for the sake of you Gentiles— 2if indeed you have heard of the stewardship of God’s grace which was given to me for you; 3that by revelation there was made known to me the mystery, as I wrote before in brief. 4By referring to this, when you read you can understand my insight into the mystery of Christ, 5which in other generations was not made known to the sons of men, as it has now been revealed to His holy apostles and prophets in the Spirit; 6to be specific, that the Gentiles are fellow heirs and fellow members of the body, and fellow partakers of the promise in Christ Jesus through the gospel, 7of which I was made a minister, according to the gift of God’s grace which was given to me according to the working of His power.
THAT is what was hidden from the prophets and from the apostles, until God made it very clear in that vision of Peter.
So, as I stated before, the posts of Scriptures you have offered in your defense are actually better suited to my application then yours.