So Jesus tells Nicodemus “You must be born again,” in order to see and enter the kingdom of God. He tells the Samaritan woman he can give her living water, i.e. a spring within her, new life, regeneration.
What would Jesus have said to one who was faithful according to the Judaism of the Old Testament — one who believed God, did not forsake the well of living water (Jeremiah 2), recognized and repented of sin, looked for the consolation of Israel / the Messiah / the fulfillment of the promises and prophets?
Would he have also told such a one of a need to be born again, or to ask for living water?
Or would he have said, “Here I am, the one you have looked for — now I give you new birth and living water.”
Are the disciples good examples? At least the ones who were living faithfully when they were called? Their faith was imperfect and full of holes, but they believed he was Messiah and they put their trust in him as such.
Who else? Simeon and Anna, who recognized the young Jesus at the Temple.
All this to say, not everyone comes to faith via a dramatic conversion experience, not even a single identifiable moment of conversion. Some grow up in faith — some grow into faith by steps.