Scriptures
Holy Spirit Baptism with the evidence of praying in tongues ...
Mark 16:17 NKJV
And these signs will follow those who believe: In My name they will cast out demons; they will speak with new tongues; they will take up serpents; and if they drink anything deadly, it will by no means hurt them; they will lay hands on the sick, and they will recover.
Acts 2:4 NKJV
And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance.
Acts 10:44-46 NKJV
While Peter was still speaking these words, the Holy Spirit fell upon all those who heard the word. And those of the circumcision who believed were astonished, as many as came with Peter, because the gift of the Holy Spirit had been poured out on the Gentiles also. For they heard them speak with tongues and magnify God.
Acts 19:1-6 NIV
While Apollos was at Corinth, Paul took the road through the interior and arrived at Ephesus. There he found some disciples and asked them, “Did you receive the Holy Spirit when you believed?” They answered, “No, we have not even heard that there is a Holy Spirit.” So Paul asked, “Then what baptism did you receive?” “John’s baptism,” they replied. Paul said, “John’s baptism was a baptism of repentance. He told the people to believe in the one coming after him, that is, in Jesus.” On hearing this, they were baptized in the name of the Lord Jesus. When Paul placed his hands on them, the Holy Spirit came on them, and they spoke in tongues and prophesied.
Romans 8:26 NKJV
Likewise the Spirit also helps in our weaknesses. For we do not know what we should pray for as we ought, but the Spirit Himself makes intercession for us with groanings which cannot be uttered.
1 Corinthians 12:8-11 NKJV
For to one is given the word of wisdom through the Spirit, to another the word of knowledge through the same Spirit, to another faith by the same Spirit, to another gifts of healings by the same Spirit, to another the working of miracles, to another prophecy, to another discerning of spirits, to another different kinds of tongues, to another the interpretation of tongues. But one and the same Spirit works all these things, distributing to each one individually as He wills.
1 Corinthians 14:2 AMPC
For one who speaks in an [unknown] tongue speaks not to men but to God, for no one understands or catches his meaning, because in the [Holy] Spirit he utters secret truths and hidden things [not obvious to the understanding]. (*he speaks mysteries. NKJV)
1 Corinthians 14:4 NKJV
He who speaks in a tongue edifies himself, but he who prophesies edifies the church.
1 Corinthians 14:4 TLB
So a person "speaking in tongues" helps himself grow spiritually…
1 Corinthians 14:13 NIV
For this reason the one who speaks in a tongue should pray that they may interpret what they say.
1 Corinthians 14:14-15 NLT, TLB
For if I pray in tongues, my spirit is praying, but I don't understand what I am saying. Well, then, what shall I do? I will do both. I will pray in unknown tongues and also in ordinary language that everyone understands. I will sing in unknown tongues and also in ordinary language so that I can understand the praise I am giving.
1 Corinthians 14:18 NIV
I thank my God I speak with tongues more than you all.
Jude 20 NKJV
But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit.