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John 3:8
"The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit."
What does that mean? You cant see the wind blowing. You can however hear it blowing through the trees or even hear it when it howls. You can physically see the initial baptism of the spirit. You do however hear it when a someone speaks in other tongues as the spirit gives them the utterance.