lull (one) into a false sense of security
To cause one to feel safe and secure in a situation that poses risks or dangers. Installing cameras at home lulled me into a false sense of security—our house still ended up getting robbed. A: "I can't believe you were able to unseat the valedictorian!" B: "I think three years of accolades lulled her into a false sense of security."
lull someone into a false sense of security
Cliché to lead someone into believing that all is well before attacking or doing someone bad. We lulled the enemy into a false sense of security by pretending to retreat. Then we launched an attack. The boss lulled us into a false sense of security by saying that our jobs were safe and then let half the staff go.