wait for the gift my Father promised .....

Holy Spirit IS The Gift. He is the Empower-er. 

wait for the gift my Father promised, ......

John baptized with water, but in only a few days you will be baptized with the Holy Spirit.” .....

you shall receive power, when the Holy Spirit is come upon you... Acts1

And when the day of Pentecost had come, they were all together in the same place. And suddenly a sound like a violent rushing wind came from heaven and filled the whole house where they were sitting. 

Before their eyes appeared tongues like flames which separated off and settled above the head of each one of them. And they were all filled with the Holy Spirit and began to speak in other languages, as the Spirit gave them ability to speak out. Acts2

[power (abilities) from Holy Spirit to speak His Word of Grace to liberate people, heal the sick, work miracles, overcome evil, be filled with love, joy, courage, peace and much more by His Grace.] 

[This post : Your spiritual language is an important indicator and establishes you in your journey with The Comforter.]:-

And these signs will follow those who believe: .......  they will speak with new tongues ..... Mark 16:17 

... amazed that the gift of the Holy Spirit was being poured out on Gentiles also; for they heard them speaking in foreign tongues and glorifying God.  Acts10

“Did you receive the Holy Spirit when you believed?”                                                                                                                              “No”, they replied, “we have never even heard that there is a Holy Spirit.”...... 

when Paul had laid his hands on them, the Holy Spirit came upon them and they began to speak with tongues and with the inspiration of prophets. Acts19 

For if I pray in an unknown tongue, my spirit prays, ......

I thank my God I speak with tongues more than you all; ......

What is the conclusion then? I will pray with the spirit, and I will also pray with the understanding.

He who speaks in an (unknown to self) tongue edifies himself, ......... 1Cor14

[when you come together] :-

... the Holy Spirit, inspires these abilities to each person individually [exactly] as He chooses.

... to another various kinds of [unknown] tongues,

For the spirits of the prophets (the speakers in tongues) are under the speaker's control [and subject to being silenced as may be necessary],

Thus [unknown] tongues are meant for a [supernatural] sign, .... 

..... do not forbid or hinder speaking in [unknown] tongues.

1Cor12+14

But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit, Jude 1:20 

[Purity of communication speaking in the language given by Holy Spirit ..... ] :-

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