Mat 11:13 For all the prophets and the law prophesied until John.

"The law" is nomos, which means "that which is in habitual practice" and is uses to mean "custom," "usage," "law," and "ordinance."

"Prophesied" is prophêteuô, which means "to be an interpreter for God."

Christ is clearly saying that John marked a transition point in history. People today either take for granted or don't realize how much the coming of Christ marked a transition in human history much less religious history. Until Christ, everyone accepted that life was brutal. Even the religions were brutal. Life was cheap. Christ was a catalyst for social change toward peace and "the universal law."

However, Christ is also saying something very subtle hear about all laws and prophets before his coming. He says that they are human interpretations of God's will. The question is: how has that changed? During Christ's life, Christ wasn't interpreting God, he was God's voice directly. But don't people just interpret God today? What has changed?

The fact that no all people are just interpreting God. Some are sometimes speaking with the Spirit of God. Christ was the channel through which we can sometimes contact the Holy Spirit.