Rasulullah (sallallahu alaihi wa sallam) said:
Sacred is the blood, the wealth and the honour of a Muslim.
So it is a great crime to enter into this sacred precincts of his life. His honour is trampled upon when he is backbited and the consequences of such an enormity is certainly arresting. Indeed, Rasulullah (alaihi ‘s-salam) said:
He who backbites and repents will be the last to enter Jannah, and he who dies without repenting from backbiting will be the first to enter the Hell-fire.
Remember, the blood, honours and welath of a believer are sacred due to the extreme value and sacredness of La ilaha illallah. The one who believes in this is immediately granted a level of wilayat with Allahu ta’ala, so do not castigate the friend of Allahu ta’ala, do not belittle him, do not amplify his fault. He had displayed some sincerity to his Kalimatush-Shahada by not indulging openly in sins, for this, he is honourable and becomes an aspirant to taqwa.