When did certain believers in the New Testament become Christians?

In the instance of the 11 remaining disciples of the original 12, were they born again

believing Christians before the day of Pentecost?

When the Samaritans believed in Acts 8, 12, did they become Christians then?

Or was it not until Peter and John came down in Acts 817 and laid their hands on them and they received the Holy Spirit.

Was Saul saved in Acts 9.6 when he said,

Lord, what wilt thou have me to do?

Or was it not until Acts 917 when Ananias went his way and entered into the house and putting his hands on him said,

Brother Saul, the Lord Jesus, who appeared to you on the road as you came, has sent me that you may receive your sight and be filled with the Holy Spirit.

Were the Ephesian-believing disciples Christians

when Paul first met them in Acts 191 through 3? Or was it not until after Paul laid his

hands on them in Acts 196? Even though they were water baptized in Acts 195. In the God-fearing House of Cornelius in Acts 10 verse 44,

the Holy Spirit fell on all them which heard the word while Peter was speaking.

This is the first biblical example of someone receiving the Holy Spirit

and speaking in tongues the first time they hear the gospel.

It is hard for me to imagine that Peter wasn't a believer when he said in Matthew,

16, 16, you are the Christ, the son of the living God, verse 17.

And Jesus answered him,

Blessed are you, Simon, bar Jonah.

For flesh and blood has not revealed this to you, but my father who is in heaven.

So what is the timing?

What is the event in light of these scriptures when someone becomes a born again Christian?

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