The prophetic world of John the Baptist proclaimed the baptism with Holy Spirit and fire by Jesus Christ, but the sign of speaking in tongues was not literally mentioned in this statement.

Luke 3:16 “I baptize you with water, but One is coming who is mightier than I, and I am not fit to untie the thong of His sandals; He will ...baptize you with the Holy Spirit and fire.”

However, in the Holy Scripture we can introduce ourselves with a more specific promise of Jesus Christ to His followers, which was addressed to His disciples:

Mark 16:17 “These signs will accompany those who have believed: in My name they will cast out demons, they will speak with new tongues.”

Despite of various tense speculations on a necessity of speaking tongues in a prayer, the sign of speaking in tongues was literally mentioned by Jesus in His promise. Moreover, on the Day of Pentecost, when His promise of the baptism of power has been fulfilled, all of His disciples were speaking in other tongues, while this event was witnessed by foreign pilgrims.

Acts 2:3-4 “...And there appeared to them tongues as of fire distributing themselves, and they rested on each one of them. And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit was giving them utterance."

There are only few Christians exist (if any) who will question a necessity and benefit of water baptism and/or baptism of Holy Spirit, but there are countless Christians who would disagree on a specific interpretation what exactly they mean and how exactly these sacraments shall be accomplished. In other words: the devil is in the details.

One group of Christians (for example, Pentecostals and Charismatic church) will teach you that the sign of speaking in tongues is an undisputedly integral sign of the baptism of Holy Spirit. Another group of Christians will assert that the sign of speaking tongues is a special gift, which predestined to few Christians only; thus, it shall not be "compulsively imposed" on all members of church. The third groups becomes even more precautious and even adversely reactive to speaking in tongues, implying such that it was and should be only one-time event in Christian history.

If these various doctrinal interpretations would bring, most likely, nothing more than a mind-blasting confusion, discouragement and despair to people's hearts, the one thing is undoubtedly obvious here: as flash-weakened sons and daughters of men, we are all doomed to perceive the Truth subjectively. Therefore, none of us can deserve to be proclaimed as an undisputed truth tellers, except one Son of Men, Jesus Christ. This means that all of us, self-proclaimed Christians, need His supervision and spiritual power in our uneasy lives, if we are want to be saved and live with Him forever.

I would like to make my message very clear: when we are talking about the power of Jesus Christ, we are talking about power of Holy Spirit, Whom He sent to us, as He promised to His disciples once:

“But I tell you the truth, it is to your advantage that I go away; for if I do not go away the Helper will not come to you; but if I go, I will send Him to you. And He, when He comes, will convict the world concerning sin and righteousness and judgment.” John 16:7,8

"And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; Even the Spirit of truth; whom the world cannot receive, because it cannot see him, neither knows him: but you know him; for he dwell with you, and shall be in you." John 14:16,17

Why the presence of Holy Spirit in our hearts is so advantageous to us? What so special about Holy Spirit to dwell not only with us, but in us (means inside our hearts)?
The Word of God is Truth, which has been personified into Body of Jesus Christ and literally encoded in the Holy Scripture, but what power makes the Bible so miraculously truthful, effective and blessing for all its faithful followers, despite all countless misconceptions of Christian doctrines and dogmas?

A Spirit of Truth. A Love of Truth. A Freedom of Truth... In other words, without spiritual power the meaning of truth (or righteousness) is not fulfilled with love, mercy, blessing or freedom. His name is Holy Spirit because the true holiness means exceptionalizm, supremacy, uniqueness, perfection, harmony, cleanness, creativity, endless blessing power. Neither angels nor demons have such perfections. Only the Spirit of Loving Heavenly Father and His Son. So, the Spirit becomes not only our Truth teller, but He becomes our Helper and Comforter.

"Likewise the Spirit also help our infirmities: for we know not what we should pray for as we ought: but the Spirit itself make intercession for us with groaning which cannot be uttered.
And He that search the hearts know what is the mind of the Spirit, because he make intercession for the saints according to the will of God." Romans 8:26, 27

Even a sign of unclear groaning in the prayer (not only speaking tongues, which cannot be uttered in meaningful words) could signify the presence of Holy Spirit. What is the mind of the Holy Spirit we, obviously, do not know and we should not know, unless if He decides to reveal His secret thoughts to our minds. But, whatever it is, the Spirit helps, comforts and protects the flash-weakened saints in the spiritual world.

If Christians believe that Holy Spirit pray and perform intercession for their salvation on heaven, they should ask themselves: how is it done, if it there is no speaking in tongues or inexplicable groaning in their prayer, which cannot be uttered. If He truly comforts our hearts with love, mercy and protection, will be our joyfulness, peace (as a result of God's grace) signified in our prayer? Will be these signs exceptional or normal? If they are truly exceptional, then how its unique appearance can be described? Apostle Paul was a very vise missionary servant of God, so he has some valid concerns about how Corinthians were praying in tongues because its exceptional appearance could have been not adequately perceived by some secular visitors. Not that Paul was against speaking tongues in churches, but he was concerned about weakened discipline and order during community church prayer.