We have debated this before and let me say that, while I still disagree with you I have found you to be a serious student of the Word, not a mocker like many here or one of the many distractors who attempt to "win the argument" by getting the thread off topic.
As I recall you hold that the Jewish Gospel omitted truths that concerned the work of the cross. (Let me know if I have it wrong) I believe this proposition - that they did not know that the sacrificial work of Christ was efficacious to take away sins of all who put their faith in Him -to be mistaken. While it is true that the themes of their sermons (at least what little was written down and recorded in the Book of Acts) concerned, not the cross, but Christ the Son risen from the Dead ascended and seated on the throne, this does not mean they did not understand the Sacrifice. It was necessary to make that point about Christ's divinity to vindicate His claims for which he has suffered an ignominious death. He was crucified for blasphemy, for saying He was equal to God. The resurrection and ascension answered the question.
The Twelve were not unaware of the purpose of the cross, not just as a means to make His death a public display, but as a means of affecting redemption. They knew it because Jesus Himself came after the resurrection and told both them and another group of disciples.
44 Then he said to them, “These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.” 45 Then he opened their minds to understand the Scriptures, 46 and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, 47 and that repentance and forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem.
(Luke 24:25-26)
He taught them all about Himself, His mission, and the reasond for His suffering in the Law, the Prophets and the Psalms which was pretty much the whole OT. Do you think Jesus might have included key scriptures like Isa. 53:5 or verses on the New Covenant like Jeremiah 31:33 without which the ritual of the Eucharist would have made no sense (Matthew 26:28). Everything they knew and taught were obviously not contained in their sermons.
"The Twelve were not unaware of the purpose of the cross, not just as a means to make His death a public display, but as a means of affecting redemption. They knew it because Jesus Himself came after the resurrection and told both them and another group of disciples."-you
The Twelve had no idea, that the Master would die, and be raised, at a time when they were preaching "the gospel of the kingdom"-it was hid from them.
" but as a means of affecting redemption."
Made up. They had no idea of the cross, as to be the means, by which they were reconciled.............redeemed.