2 Thessalonians 2:2

2:2 not to be easily shaken from your composure or disturbed by any kind of spirit or message or letter allegedly from us, to the effect that the day of the Lord is already here.

2 Thessalonians 3:6

Response to the Undisciplined

3:6 But we command you, brothers and sisters, in the name of our Lord Jesus Christ, to keep away from any brother who lives an undisciplined life and not according to the tradition they received from us.