Matthew 11:12 – “From the days of John the Baptist until now, the kingdom of heaven has been forcefully advancing, and forceful men lay hold of it.” (NIV 1984)
~ What follows now are some notes from Matthew (Zondervan Exegetical Commentary on the New Testament) by Grant Osborne, my old prof.
“The problem has to do with the words biazetai (“is subject to violence”) and biastai (“violent people”). These words are found in said verse side by side and can be understood either positively (“forceful advance”) or negatively (“suffering violence”).
Four Ways to Understand this Verse:
(A) Totally Positive: “the kingdom forcefully advances [through God], and forceful people [the disciples] seize it”
(B) Totally Negative: “the kingdom suffers violence [persecution], and violent people [the leaders] plunder it”
(C) Negative/Positive: “the kingdom suffers violence, but forceful people lay hold of it”
(D) Positive/Negative: “the kingdom is forcefully advancing, but violent people plunder it.”
~ Arnold/Osborne think that its best to see biazetai as passive rather than middle (“forcefully advancing”) and thus as a negative. They also think that biastai ought to be seen in its common negative use as “violent people”.
~ According to Arnold/Osborne, the verse is basically speaking of persecution that the church experiences at the hands of violent people. What was John the Baptist’s fate?
NET BIBLE TRANSLATION:
11:12 From  the days of John the Baptist until now the kingdom of heaven has suffered violence, and forceful people lay hold of it. 
 tn Here δέ (de) has not been translated.
 tn Or “the kingdom of heaven is forcibly entered and violent people take hold of it.” For a somewhat different interpretation of this passage, see the note on the phrase “urged to enter in” in Luke 16:16.
12 From the days of John the Baptist until now the kingdom of heaven has suffered violence,[a] and the violent take it by force.
[a] Matthew 11:12 Or has been coming violently
“12 From the days of John the Baptist until now, the kingdom of heaven has been subjected to violence,[a] and violent people have been raiding it.”