Jesus’ verdict on John (Matthew 11:7-17).
7-9. John’s preaching had created a sensation. … Jesus now show(s) the real significance of John. 10. John is not just a prophet, but the messenger of Malachi 3:1. …
11. John is thus the greatest of prophets, indeed of all men up to his time — great, that is, in his place in God’s purpose, not necessarily in his personal worth. But that purpose was leading to a new order, the kingdom of heaven, of which John was only the herald, and which is the fulfilment of all that went before. To be in that kingdom, even as the least, is to be greater (in the same sense) than the great man who proclaimed its coming, but remained as yet outside it. …
John is thus seen, in his capacity as the forerunner, as standing outside the kingdom of heaven. He is the last of the old order, as the subsequent identification with Elijah (v. 14) will make clear. In v. 12 his ‘days’ are seen as the time when God’s kingdom begins to be a reality, but his own place is rather with the Old Testament (v. 13). It was not his privilege to be involved in the ministry of Jesus, with its new perspective and dynamic. To speak of him as ‘outside the kingdom of heaven’ in this sense is not of course to pronounce on his personal salvation (any more than that of any of the Old Testament saints), but on his place in the development of God’s plan.
Verse 11 suggests, as v. 12 will make explicit, that now with the ministry of Jesus the kingdom of heaven which John proclaimed is already a reality. The old order has been superseded.
12. John’s coming precipitated a new situation, described here in terms of violence. … This violence began with the time of John’s preaching, because that was when the kingdom of heaven began to be proclaimed, even if John himself was not ‘in’ it. … v 11 showed his exclusion from the subsequent kingdom of heaven. He belongs to the forward-looking (prophesied)era of the Old Testament. (Tyndale New Testament Commentaries: Matthew, R.T. France, pages 197, 198, 199)