The Bible mentions about Baptism of the Holy Spirit, namely in the Gospel of John. The Gospel of John mentions seven “I am” statements by Jesus, and reflects Jesus as the Son of God, unlike other Gospels, such as the Gospel of Luke, which emphasises Jesus as the Son of man. Jesus is both Son of man and Son of God. A duality exists. In Quantum Physics, even scientists can confirm that mind-bending dualities exist, such as Wave-Particle duality, where a quantum entity is both a wave and a particle. God created Quantum Physics, so it is not surprising that Jesus is both the Son of man and Son of God.
In John 3:5, Jesus states “Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.” According to Matthew Henry’s commentary, one form of Baptism is here mentioned in terms of a duality, water and Spirit, in terms of being Born Again. The Baptism of the Holy Spirit (hence why Spirit has a capital “S” in this verse) purifies like water and is also being Born Again of the Spirit, like fire. The Bible mentions many times the Holy Spirit, such as the Fruits of the Holy Spirit, the Gifts of the Holy Spirit and Pentecost. The Holy Spirit came down on the Apostles fifty days after Jesus resurrected, like cloven tongues of fire, which is called Pentecost (“Pente” meaning fifty). Pentecostal Christians rely on and emphasise a direct relationship with the Holy Spirit, where He directs and guides Christians through-out their lives.
The Baptism of the Holy Spirit is a dynamic experience, where the believer can undergo a dynamic transformation in Faith, demonstrates Fruits of the Spirit, and may be prepared for missionary/ministry work by reaching a new measure of undeniable Faith in Jesus Christ. There are many Christians (of all denominations that believe the Word of God and in Jesus) who have received a palpable filling of the Holy Spirit, an inner warmth/fire, and many times speaking in tongues, which is evidence of the Holy Spirit, just like the Apostles, and like water, a purifying of one’s nature towards sanctification and being set-apart to God (the definition of ‘Holy’).
Nicodemus, who was a teacher to Israel, tries to grasp the meaning of being Born Again, by visiting Jesus at night so he would not be seen by the religious establishment of the time, the sanhedrin, where the sanhedrin ended up rejecting Jesus. Later, Nicodemus helps prepare Jesus’ body for burial with Joseph after the crucifixion. Jesus mentions to Nicodemus that to enter the kingdom of God a man must be Born Again. This is being Baptised of the Holy Spirit, Born Again of the Spirit, and is an undeniable belief and confirmation that God/Jesus/Holy Spirit, the Godhead and Trinity, are real.