The Dimond brothers (Sedevacantists) have a good video giving an overview of the Ravi Zacharias sex scandal:
Ravi Zacharias Sex Scandal Shocks Protestant World (Catholic Analysis)
Protestants are in a bit of a quagmire here. I mean, in their theology (Perseverance of the Saints/Eternal Security), Ravi was saved, even when he engaged in such activities, and at best, would fall under the "fatherly disciplines" of God or, alternatively, they will have to claim Ravi was always unregenerate, and that will cast a dark cloud over his writings and those who claim to have come to know Jesus as a result.
One is reminded of King David--someone who outwardly was "Godly" but fell into sexual sin (though David was truly saved, and was re-justified as he truly repented; Ravi was never saved to begin with). See:
King David Refutes Reformed Soteriology (cf. Refuting Christina Darlington on the Nature of "Justification")
Of course, Ravi was worst than a sex fiend: he was a heretic (Protestant) (cf. Matt 10:28).
Image of Ravi with another damnable false teacher:
