I committed Haram acts with woman on Internet and made Taubah; however, a brother who calls himself a Salafi always attacks me for my past sin and does not accept that I have made Taubah and calls me a Munafiq. How can I respond to him?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. Allah Says (interpretation of meaning): {And He it is Who accepts repentance from His slaves, and forgives sins, and He knows what you do.}[42:25]. The Prophet (Sallallahu Alaihi wa Sallam) said: A repentant from his sin becomes just like the one who does not have any sin . The Prophet (Sallallahu Alaihi wa Sallam) also said: Every son of Adam commits sin, and the best of the sinners is the repentant . If you have made sincere repentance according to the Shariah, then no one has the right to rebuke you even if the sin was very repulsive, because the repentance erases all the sins. Allah Says (interpretation of meaning): {Say: "O 'Ibâdî (My slaves) who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allâh, verily Allâh forgives all sins. Truly, He is Oft-Forgiving, Most Merciful.}[39:53]. Moreover, Allah may convert the sins of a repentant into good deeds. Allah Says (interpretation of meaning): {Except those who repent and believe (in Islâmic Monotheism), and do righteous deeds, for those, Allâh will change their sins into good deeds, and Allâh is Oft-Forgiving, Most Merciful.}[25:70]. Therefore, the person who is scoffing or rebuking you is committing a sin. Probably Allah may punish him for this act. The Prophet (Sallallahu Alaihi wa Sallam) said: If anyone reviles his brother for a sin, he will not die before committing it himself . Imam Ahmad said, it means any sin of which he has repented. The Prophet (Sallallahu Alaihi wa Sallam) also said: Do not exult over the misfortune of a brother for Allah might have Mercy on him and involve you in misfortune . [ Al-Tirmizi ] So, the person who is rebuking should fear that the threat may inflict him. Know that every heart is between the two fingers of al-Rahman. If He wants He makes it steadfast, and if He wants He deviates it. We advise you to follow the instruction given below: 1. Let him read this Fatwa. 2. Forgive him for his offense and bad behavior. Allah Says (interpretation of meaning): {…but whoever forgives and makes reconciliation, his reward is due from Allâh….}[42:40]. Allah also Says: {…Repel (the evil) with one which is better (i.e. Allâh ordered the faithful believers to be patient at the time of anger, and to excuse those who treat them badly), then verily! he, between whom and you there was enmity, (will become) as though he was a close friend.}[41:34]. 3. Seek help of some good, reliable and pious persons who can exhort him and advise him to avoid this bad practice. 4. If all the above matters do not work then abandon him by severing your relations with him. Allah knows best.