There are few topics as controversially discussed in (Western) Christianity as the subject of baptism in the Spirit, especially when it comes to the gift of speaking in tongues (glossolalia).

The video seminar serves to give interested Christians, without pressure or coercion, a general overview of the subject of baptism in the Spirit — or perhaps better: the release of the Holy Spirit in the life of Christians. And what is the biblical gift of speaking in tongues, promised to us through Jesus Christ, actually about?

1. Martin's personal story
2. Baptism means release
3. What does "baptism" actually mean?
4. New birth and baptism in the Spirit
5. No reward for holiness
6. Why language or voice?
7. The two kinds of speaking in tongues

Further Bible passages:

The great chapters on speaking in tongues:
1 Corinthians 12 and 14

Baptism in the Holy Spirit in the book of Acts:
2,1-18
10,44-48
11,15
19,1-7

John the Baptist:
I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire 
Matthew 3:11 (similarly in Luke 3:16 and Mark 1:8)

Jesus:
John baptized with water, but you baptized with the Holy Spirit not many days from now.
Acts 1:5 (quoted again in Acts 11:16)

Jesus:
I will ask the Father, and he will give you another Helper [Comforter, Advocate, Helper, literally: the one called alongside to help] to be with you forever,
John 14:16

Jesus (at the time of the ascension):
And these signs will accompany those who believe: in my name they will cast out demons; they will speak in new tongues; they will pick up serpents, and if they drink any deadly poison, it will not hurt them; they will lay their hands on the sick, and they will recover. …
And they went out and proclaimed everywhere, while the Lord worked with them and confirmed the message by accompanying signs.
Mark 16:17-20

And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance.
Acts 2:4

While Peter was still saying these things, the Holy Spirit fell on all who heard the word. And the believers from the circumcision party who had come with Peter were amazed, because the gift of the Holy Spirit was poured out even on the Gentiles; for they were hearing them speaking in tongues and extolling God. Then Peter declared, "Can anyone withhold water for baptizing these people, who have received the Holy Spirit just as we have?"
Acts 10:44-47

When Paul had laid his hands on them [the disciples in Ephesus] , the Holy Spirit came on them, and they were speaking in tongues and prophesying.
Acts 19:6

Bible passages on the subject of the prayer language:

For if I pray in a tongue, my spirit prays but my mind is unfruitful. What am I to do? I will pray with my spirit, but I will pray with my mind also; I will sing praise with my spirit, but I will sing with my mind also.
1 Corinthians 14:14-15

Now I want you all to speak in tongues…
1 Corinthians 14:5

I thank God that I speak in tongues more than all of you.
1 Corinthians 14:18

Praying at all times in the Spirit, with all prayer and supplication…
Ephesians 6:18

The one who speaks in a tongue builds up himself…
1 Corinthians 14:4

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

Likewise the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words  
Romans 8:26

General Bible passages on handling baptism in the Spirit:

And the spirits of prophets are subject to prophets.
1 Corinthians 14:32

Therefore, brothers, earnestly desire to prophesy, and do not forbid speaking in tongues!  
1 Corinthians 14:39