In Pergamos persecution had already taken the life of one member of the church. The threats now had substance. The outward situation was precarious, but Jesus sees a greater danger for this church rising from within.
Longfellow translated the words of a German poet (Friedrich von Logau) like this:
“Though the mills of God grind slowly, yet they grind exceeding small; Though with patience stands He waiting, with exactness grinds He all.”
The point is that God’s judgment, though it may not come quickly by our standards, is certain and very exact.
We come today to the end of a first-century sermon written by an author trained in Jewish rabbinical tradition. He wrote this to a congregation of Jewish Christian believers, probably residing in Rome. He has encouraged them to remain faithful to Jesus no matter what. And he wants them to understand that knowing and following Jesus is far and away better than any religious tradition they can ever find anywhere else.