And his father Zechariah was filled with the Holy Spirit and prophesied saying,
"Blessed be the Lord God of Israel, for he has visited and redeemed his people,
and has raised up a horn of salvation for us in the house of his servant David,
as he spoke by the mouth of his holy prophets from of old,
that we should be saved from our enemies and from the hand of all who hate us;
to show the mercy promised to our fathers and to remember his holy covenant,
the oath that he swore to our father Abraham, to grant us
that we, being delivered from the hand of our enemies, might serve him without fear,
in holiness and righteousness before him all our days.
And you, child, will be called the prophet of the Most High; for you will go before the Lord to prepare his ways,
to give knowledge of salvation to his people in the forgiveness of their sins,
because of the tender mercy of our God, whereby the sunrise shall visit us from on high
to give light to those who sit in darkness and in the shadow of death, to guide our feet into the way of peace." (ESV)
Because Zechariah first doubt the message that Gabriel brought to him from the Lord, he was struck with a form of muteness until the day that his promised child was circumcised. When he did speak, he was used by the Lord as a vessel of praise. The words that came from Zechariah were truly not his own, but were from God himself, the third person of the trinity, the Holy Spirit.
God's inspired Word (Holy Scriptures) is the best vehicle that a believer can use to praise Him. This is another reason that a believer should be immersed in Scriptures. So, that when the believer prays to praise God, the Holy Spirit can bring back to that believer's memory those Scriptures that the believer has read that praises God for his many attributes.