All of the mysteries are layed out pretty good in the scriptures...Shouldn't be any questions about those...
It's clear (to me) that when the church was started it was aimed at the Jews who were law compliant...Lots of things were unclean, even other people...
It was revealed in Acts 10 that a change was taking place to make things clean and lawful and ultimately remove people from the burden of the law...
This didn't happen with a bang...It was a gradual process...
To try to pinpoint the date or specific scripture when this change came in with a bang is impossible...It didn't happen that way...But I think we can all see that it happened...
Acts 10 surely shows the shock to Peter and those with him when Cornelius and those with him received the Holy Spirit only after believing. Peter obviously thought more was needed before that would happen.
Just as Christ did not give Paul a SINGLE vision and revelation, but a series of visions and revelations:
"It is not expedient for me doubtless to glory. I will come to visions and revelations of the Lord." (2 Cor. 12:1).