Baptism in the Holy Ghost with the
  evidence of speaking in tongues

1 Corinthians 13:8 Charity never faileth: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away.
9 For we know in part, and we prophesy in part.
10 But when that which is perfect is come, then that which is in part shall be done away.
14:39 Wherefore, brethren, covet to prophesy, and forbid not to speak with tongues.
That which is perfect is Jesus, and He has not came back yet.
The Holy Ghost with speaking in tongues as the evidence is just as real today as on the day of Pentecost.  We still have prophesy and knowledge today also.  These have not vanished away because Jesus has not came back after His church yet.

Acts 2:1 And when the day of Pentecost was fully come, they were all with one accord in one place.

2 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.

3 And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.

4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance (a spoken word, statement, or vocal sound)

The 120 in the upper room were now filled with the Holy Ghost, but they were already saved.  They had to be led by the Spirit before they could of ever got saved.  Now there was another blessing from God call the receiving of the Holy Ghost and speaking utterance.

Acts 19:1 And it came to pass, that, while Apollos was at Corinth, Paul having passed through the upper coasts came to Ephesus: and finding certain disciples,
2 He said unto them, Have ye received the Holy Ghost since ye believed? And they said unto him, We have not so much as heard whether there be any Holy Ghost.
These men were disciples of Jesus Christ and have been under John the Baptist ministry.  These were saved men.  We see in verse 2 that these men were also believers.  You do not get it all when you get saved.  You can not be saved without the Holy Spirit leading you to get saved, but the Baptism in the Holy Ghost is a different event. There are there aspects of salvation.  There is salvation, sanctification and the Baptism of the Holy Ghost.
In the second chapter of acts the 120 people including Mary the mother of Jesus tarried for 10 days.  They were in one mind and one accord then the Holy Ghost fell upon them.  Jesus rose from on the third day and was on earth for 40 days.  He told the disciples to go to the upper room and tarry until they receive power from the Holy Ghost.
37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?
38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
39 For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
             We see above that the Holy Ghost is a promise for you,
                  and to your children, and to all that are afar off.
This includes this generation that we are living in.  God does not give bad gifts to his children.
Mark 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
17 And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues;
18 They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover.
1 Corinthians 14:39 Wherefore, brethren, covet to prophesy, and forbid not to speak with tongues.
Ephesians 6:18 Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;
19 And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel,
There is the Father, the Son, and The Holy Ghost.  The Holy Ghost is the third part of the trinity, and the Holy Ghost the third aspect of salvation.  There is salvation, sanctification, and Baptism in the Holy Ghost.
Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
                This gift is free just as the gift of salvation is free.
Acts 7:51 Ye stiffnecked and uncircumcised in heart and ears, ye do always resist (fight against) the Holy Ghost: as your fathers did, so do ye.
Evil people who are not of God forbid Holy Ghost men and women to speak in tongues.  They are stiff necked and uncircumcised in heart.  They are lost, and I don't care what church they are preaching. Matthew 3:11 I indeed baptize you with water unto repentance. but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:
1 Thessalonians 5:19 Quench not the Spirit
DO NOT TRY TO PUT OUT THE FIRE OF GOD AND HIS HOLY SPIRIT
Isaiah 28:11 For with stammering lips and another tongue will he speak to this people.

Jude 1:17 But, beloved, remember ye the words which were spoken before of the apostles of our Lord Jesus Christ;

18 How that they told you there should be mockers in the last time, who should walk after their own ungodly lusts.

19 These be they who separate themselves, sensual, having not the Spirit.

20 But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,

We are to be praying in the Holy Ghost, and those who do not have the Holy Spirit will separate themselves from the ones that are filled with the Holy Ghost.

This is a gift from God when we get you closer to Him.  When we speak in an unknown tongue we speak directly to God, and Satan cannot understand us.

1 Corinthians 14:1 Follow the way of love and eagerly desire gifts of the Spirit, especially prophecy.

2 For anyone who speaks in a tongue does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit.

3 But the one who prophesies speaks to people for their strengthening, encouraging and comfort.

4 Anyone who speaks in a tongue edifies themselves, but the one who prophesies edifies the church.