John Chrysostom
Catena Aurea · Lukasevangelium 12
Also I say unto you, Whosoever shall confess me before men, him shall the Son of man also confess before the angels of God: But he that denieth me before men shall be denied before the angels of God. And whosoever shall speak a word against the Son of man, it shall be forgiven him: but unto him that blasphemeth against the Holy Ghost it shall not be forgiven. And when they bring you unto the synagogues, and unto magistrates, and powers, take ye no thought how or what thing ye shall answer, or what ye shall say: For the Holy Ghost shall teach you in the same hour what ye ought to say.
There are other modes also of denying which St. Paul describes, saying, They profess that they know God, but in works they deny him. (Tit. 1:16.) And again, If any provide not for his own, and specially for those of his own house, he hath denied the faith, and is worse than an infidel. (1 Tim. 5:8.) Also, Flee from covetousness, which is idolatry. (Col. 3:5.) Since then there are so many modes of denial, it is plain that there are many likewise of confession, which whosoever has practised, shall hear that most blessed voice with which Christ greets all who have confessed Him. But mark the precaution of the words. For in the Greek he says, Whosoever shall confess in Me, shewing that not by his own strength, but by the aid of grace from above, a man confesses Christ. But of him who denies, He said not “in Me,” but me. For though being destitute of grace he denies, he is nevertheless condemned, because the destitution is owing to him who is forsaken, or he is forsaken for his own fault.