Build yourself on Holy Ghost

Hold fast sound words. Keep that good thing which was committed to you by the Holy Ghost. What good thing? The unfeigned faith. How do you keep it? By the gift of the Holy Ghost that was given by the laying on of hands.
Someone said, "What good is all that talking in tongues? Nobody can understand it." The Bible says you speak not unto men, but unto God. Ask yourself
this: Would it be of any benefit to have a direct communication with God? Paul said it will build you up. It will edify you. Then Jude adds some light to the subject by saying: But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,
Keep yourselves in the love of God,
looking for the mercy of our Lord Jesus
Christ unto eternal life.
—Jude 20-21
Praying in the Holy Ghost will build you up in your most holy faith. He didn't say it would give you faith. He didn't say that God would build you up. You build yourself up in your most holy faith by
praying in the Holy Ghost.