luke 9:26 For whosoever shall be ashamed of me and of my words, of him shall the Son of man be ashamed, when he shall come in his own glory, and in his Father's, and of the holy angels. - Free Bible Online

      26. ashamed of me, and of my words--The sense of shame is one of the strongest in our nature, one of the social affections founded on our love of reputation, which causes instinctive aversion to what is fitted to lower it, and was given us as a preservative from all that is properly shameful. When one is, in this sense of it, lost to shame, he is nearly past hope (Zec 3:5; Jer 6:15; 3:3). But when Christ and "His words"--Christianity, especially in its more spiritual and uncompromising features--are unpopular, the same instinctive desire to stand well with others begets the temptation to be ashamed of Him, which only the 'expulsive power' of a higher affection can effectually counteract.
      Son of man be ashamed, when he cometh, &c.--He will render to that man his own treatment; He will disown him before the most august of all assemblies, and put him to "shame and everlasting contempt" (Da 12:2). "Oh shame, to be put to shame before God, Christ, and angels!" [BENGEL].

JFB.