what does the bible say?

Matthew 11:11 states: “Assuredly, I say to you, among those born of women there has not risen one greater than John the Baptist; but he who is least in the kingdom of heaven is greater than he.”

"Among those born of women there has not arisen one greater than John the Baptist" - In Luke 1:15-17 we read:  “For he (John) will be great in the sight of the Lord, and shall drink neither wine nor strong drink.  He will also be filled with the holy Spirit, even from his mother’s womb.  And he will turn many of the children of Israel to the Lord their God.  He will also go before Him in the spirit and power of Elijah, ‘to turn the hearts of the fathers to the children,’ and the disobedient to the wisdom of the just, to make ready a people prepared for the Lord.’”

Among all the prophets of the Old Testament, God raised up none greater than John (as Luke expounds it).  And as Christ said, “among those born of women (born as a human) there has not risen one greater than John the Baptist.”

"But he who is least in the kingdom of heaven is greater than he" – However, as great as John was (in character and in deeds) during Jesus’ day his position as forerunner was inferior to that of the least person in the kingdom of heaven.  John was a great and good man, yet not perfect (Romans 3:23); therefore he, as a human, fell short of possessing the perfect righteous character of any, and all, of the future glorified saints (I Corinthians 15:53-54; I John 3:2).

This verse does not say John the Baptist will be the least in the kingdom of heaven once he is resurrected and born into the Family of God, only that as a human he could not attain to the least of the glorified saints in God’s future kingdom.