Lulled into a false sense of security

To be lulled into a false sense of security means to being made to feel safe and relaxed when danger or problems still exist.

The word lulled comes from lull, meaning to calm or soothe someone, like a lullaby quieting a child. In this phrase, that calm feeling is misleading because the real risk has not gone away.

The quiet weather lulled the hikers into a false sense of security before the storm arrived.