For Luke, the time of the Church is a time when the Spirit of the absent Lord, like a burning fire, will accomplish his work of judgment in human hearts. In the mission of the Church, just as in the pre-resurrection mission of Jesus, the call for decision is a call for "division." This division will reach into the most intimate personal relationships, into "one house" (Ellis 182).
The dangers of not watching for current spiritual weather indicators are more serious than lugging an umbrella around all day under sunny skies or getting caught in a downpour without an umbrella.
They are ignoring the significance of Jesus' death and resurrection, in other words, refusing to repent. We will find out in chapter 13 the consequences of that interpretation of current events.
E. Earle Ellis, The New Century Bible Commentary on The Gospel of Luke (Greenwood, South Carolina: The Attic Press 1977)
Ian Howard Marshall, Commentary on Luke in the New International Greek Testament Commentary Series (William B. Eerdmans Publishing Company, 1978).
Michael F. Patella, O.S.B, The Gospel According to Luke in the New Collegeville Bible Commentary Series (Collegeville, MN: Liturgical Press, 2005).