Passage
whose mouth it behoveth to stop, who whole households do overturn, teaching what things it behoveth not, for filthy lucre's sake.
Titus 1:11 (YLT)
Nearby Context
Titus 1:9 holding--according to the teaching--to the stedfast word, that he may be able also to exhort in the sound teaching, and the gainsayers to convict;
Titus 1:10 for there are many both insubordinate, vain-talkers, and mind-deceivers--especially they of the circumcision--
Titus 1:11 whose mouth it behoveth to stop, who whole households do overturn, teaching what things it behoveth not, for filthy lucre's sake.
Titus 1:12 A certain one of them, a prophet of their own, said--`Cretans! always liars, evil beasts, lazy bellies!'
Titus 1:13 this testimony is true; for which cause convict them sharply, that they may be sound in the faith,
Study Lenses
The verse centers on "whose", "mouth", "behoveth", "stop", "whole", "households", "overturn", and "teaching". It is saying that the verse draws attention to "whose" and "mouth", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "for there are many both insubordinate vain-talkers..." into verse 12's "A certain one of them a prophet...", so "whose" and "mouth" belong inside that flow. In Titus context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "whose" and "mouth" with trust shaped by these words, not by a vague optimism outside the passage.