Christ. My son, do not take it to heart if others think ill of you, and say unpleasant things about you. Consider yourself to be even worse that they imagine, and regard yourself as the weakest of men. If your inner life is strong, you will not pay much heed to passing words. A wise man remains silent when beset by evil; he turns to Me in his heart, and is untroubled by man's judgments.

Do not let your peace depend on what people say of you, for whether they speak good or ill of you makes no difference to what you are. True peace and joy is to be found in Me alone. He who is neither anxious to please nor afraid to displease men enjoys true peace. All unrest of heart and distraction of mind spring from disorderly affections and groundless fears. - Thomas a' Kempis - "The Imitation of Christ"

Thomas a' Kempis seems to build a lot from the John 15 passage and especially the "if a man remains in me and I in Him" line of verse 5. I'm not sure that I agree totally with the last line of his quote above (It seems Christ could be described as having 'unrest of heart' in the garden) but the rest I find difficult but assuring.