At Pentecost there was no fire.

The divided tongues like fire came down to each one of the disciples and they spoke different languages so that all the people there could understand what they said without translators. In the OT times, God appointed his prophets by touching their mouths and putting his word into their mouths so that they might declare it to his people. Therefore, a prophet was the spokesman of God, and is usually called "the mouth of the Lord."

Jesus as the Prophet

Jesus, called the Word as well as God, came into this world as the great prophet for the ministry of the word. He taught the kingdom of God to his people and trained his disciples to be prophets after his departure. The risen Christ appointed his disciples to be prophets, giving them the ministerial task of the word and asking the Father to seal them as his prophets.

The Baptism of the Holy Spirit

Thus, the baptism of the Holy Spirit was the installation ceremony for the disciples to be the new covenant prophets, as it was for the prophets of OT times. The disciples were to go out to the ends of the earth to proclaim his word. Those baptized by water are simultaneously baptized by the Holy Spirit and are given the office of the new covenant prophet.