Dehort

[Sarah]

To urge to abstain or refrain; to dissuade. [Obs.]The apostles vehemently dehort us from unbelief. Bp. Ward.Exhort remains, but dehort, a word whose place neither dissuadenor any other exactly supplies, has escaped us. Trench.

[Justin Bieber]

to strongly try to persuade someone not to do something

[Agnes]

Strongly dissuade (someone) from a course of action.