What is the meaning of Matthew 3:11 "He shall baptize you with the Holy Sprit and fire?"
The question you raise is one often misunderstood. Many would link these verses with the coming down of the Holy Spirit at Pentecost, and in application it is appropriate (Acts 2). However, the only safe way to interpret scripture is in its context.
Matthew's Gospel is the presentation of the King and is largely taken up with the truth of the Kingdom. John the Baptist in speaking says, "the Kingdom of the heavens is drawn nigh" (Mt. 3:2). John is baptizing Jews who are repenting in light of the coming of their Messiah. There is One coming who will baptize with the Holy Ghost and with fire. The Lord Jesus, as that One who is also the King, has been rejected, and His earthly Kingdom has been deferred until He returns as the Mighty One who will reign for the Millennium. Until that time arrives, the Holy Spirit will be poured out upon those who repent, both Jew and Gentile, the redeemed who are introduced into the Kingdom of the Heavens, and then the fire of judgment upon the rest (Mt. 25). In the meantime, the Kingdom of the Heavens as set out in the seven parables of Mt. 13 is now the "heavenly side" of the Kingdom. That is the kingdom ruled from heaven, the King being absent in Heaven and the citizens of the Kingdom waiting for His return at the rapture. Then the clock will start again for the introduction of the earthly Kingdom. What a wondrous majestic answer to the rejection in Matthew 11 and 12 will be seen in that day of Glory. In the meantime, "what manner of persons ought we to be?" (2 Pet. 3:11).