I am saying you will be a more effective witness if you are endued with power from on high and receive the gift of tongues. The scripture supporting this is when Jesus said wait until you are endued with power from on High and you shall be my witnesses etc...
The scritpure from Jude 20 to build up your most holy faith praying in the Holy Ghost supports building up your faith praying in tongues. Paul said when he prayed in tongues he was praying in the spirit. Jude was talking about the same thing. F.F. Bruce agrees with this even though he was a cessationists. I am pretty sure I read his commentary that Jude was probably talking about tongues. And he explains why from the Greek.
I Corinthians 12
27 Now you are the body of Christ, and each one of you is a part of it. 28 And God has placed in the church first of all apostles, second prophets, third teachers, then miracles, then gifts of healing, of helping, of guidance, and of different kinds of tongues. 29 Are all apostles? Are all prophets? Are all teachers? Do all work miracles? 30 Do all have gifts of healing? Do all speak in tongues? Do all interpret? 31 Now eagerly desire the greater gifts.
I Corinthians 13
1 If I speak in the tongues a of men or of angels, but do not have love, I am only a resounding gong or a clanging cymbal
Jude 20
17 But, dear friends, remember what the apostles of our Lord Jesus Christ foretold. 18 They said to you, “In the last times there will be scoffers who will follow their own ungodly desires.” 19 These are the people who divide you, who follow mere natural instincts and do not have the Spirit.
20 But you, dear friends, by building yourselves up in your most holy faith and praying in the Holy Spirit, 21 keep yourselves in God’s love as you wait for the mercy of our Lord Jesus Christ to bring you to eternal life.
22 Be merciful to those who doubt; 23 save others by snatching them from the fire; to others show mercy, mixed with fear—hating even the clothing stained by corrupted flesh.
I Cor 12 indicates not all gifts are given to all people, including tongues.
I Cor 13 states it's love, not tongues, that matters.
Jude 20 shows zero contextual implications that tongues are being referred to in verse 20. Praying in the Holy Spirit does not mean tongues, except to charismatics. No evidence to support that intention in this verse.