We can say many words but when the Holy Spirit brings something to our mind and we speak "that word" we witness to God and Jesus and we know exactly what the problem is when we counsel another person.
We can speculate and avail nothing. We can try to speak something and say nothing of real value.
But when we speak as the Holy Spirit gives us a word to speak, we speak truth and the gates of hell cannot stand against that word that is revealed from God by the Spirit.
Acts 1:8 Jesus says: But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto ME both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.
Over and over, during this life, God brings us a word by HIS Spirit. It is not a one time event. The Holy Spirit lives in us and speaks the Word from God through us. When that happens, the power of God is there in that word.
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