"Behold, I will send the promise of My Father upon you; but tarry ye in the city of Jerusalem, until ye be endued with power from on high." -Luke 24:49
The promise of the Father was to send the Holy Spirit to the disciples and empower them to serve as Christ's witnesses to the world. On the day of Pentecost (50 days after the Lord's resurrection) the manifestation of the Holy Spirit came like a mighty wind and filled the disciples with power from on high.
That experience was accompanied by the manifestation of speaking in other tongues as the Spirit gave them to each one (120 people in all).
Scripture also calls this promise the baptism with the Holy Spirit. This baptism is always accompanied by the manifestation of speaking in other tongues as the Holy Spirit gives them. Speaking in other tongues means just that, speaking in another language.
In the case of the disciples on the day of Pentecost, they spoke languages known to those who heard them speak. Now, the Bible mentions another kind of language which Paul calls "angelic". We do not know how this language is constructed; whether it has vowels and consonants.
What we do know is that they communicate a message that God understands. When we experience speaking in tongues, we are communicating praise, prayers and petitions to God. It is the Holy Spirit's way of helping us reach God when we are limited in our humanity.
While this experience is magnificent and precious, it is not the end, for the Lord indicates to us through this experience that we have been empowered by the Holy Spirit to be witnesses for Jesus Christ.
Remember, it is a promise. Ask the Father today in Jesus' Name to give you that promise. Remember to do it with Faith and Patience.
-Pastor Omar Valcárcel