I see what's going on. You were/ are thinking of 'the church' as meaning the moment when two dispensations change their name from one to the other, and so it would be the division called "the Gospel"(?).
As far as that benchmark, I see where the Lord said,
"The Law and the Prophets were until John:
since that time the Kingdom of God is Preached, and every man presseth into it."
Then, I see the word 'church' that you have in the following posts and was using it to refer to all the saved folks in the New Testament Era. Those I call the Kingdom of God that every saved soul is born into, at the time of their New Birth.
I see the word 'church' in the Bible as being 'what it meant to everyone then' and that was 'an organized, called out assembly that is always local and self-governed', that Jesus Divinely Founded and Continued to build, or edify, as it says in
Matthew 16:18;
"And I Say also unto thee, That thou art Peter,
and upon This Rock I Will Build My Church;
and the Gates of Hell shall not prevail against it."
"And I Say also unto thee,
That thou art Peter (in the Greek his name means a small stone),
then the word Jesus uses to refer to Himself as "this Rock", means a huge, massive slab of foundation rock, )"and upon This Rock" (so, it is a play on words in the Greek ('you're a small pebble and I Am a massive boulder, Jesus is saying.)
In other words, "I Will Build My Church; (Jesus' Divinely Designed and Originated kind of called out assembly, which were made up of Scripturally baptized saved souls, who were to carry out the Divine Ordinances, the Great Commission, and Worship God, not forsaking the assembling of themselves together".
"Not forsaking the assembling of ourselves together, as the manner of some is;
but exhorting one another: and so much the more, as ye see the Day approaching." Hebrews 10:25.
And Jesus Promised His Ordained assembly of the Apostles there listening to Him that the influence of Satan was never going to completely overrun all of His various church bodies spread around the globe and spread over the centuries, where He said, "the Gates of Hell shall not prevail against it."
Jesus is at that time speaking to His assembled church body that He Originated, using the Greek word for a called assembly, and in this case He had Gathered His closest followers who He had called out to serve Him as what He then called "my church", meaning Jesus' Own type of called out assembly that He was
"Building", by Giving His Apostles the Word of God and the Gospel and the Divine Ordnances.
Jesus began "Building" For His version of what a church or local body of specific people where to be comprised of in His case, Jesus Chose those men who had been baptized by the Authority of God by the one man who had, because he was Sent by God to baptize, and that was John the Baptist.
So, when Jesus called the Apostles together, after He had chosen them, they assembled in an official Organized corporate entity, Jesus church assemble there in Jerusalem, with Jesus as their Head.
That is exactly what is said and meant, in
I Corinthians 12:28;
"And God hath Set some in the church, first Apostles,
secondarily Prophets, thirdly Teachers, after that Miracles,
then Gifts of Healings, Helps, Governments, Diversities of Tongues."
That is where the Bible says Jesus began His kind of churches.