שבת שלום

4. How can one rectify negative impressions that remain from the past?
Answer: Firstly we must remember what is written in Tanya, that a person who is at the level of ‘beinoni’ (one who doesn’t sin but still possesses an evil inclination) which is the common category, can control his thought, speech, and deed, but not necessarily his feelings. Therefore whoever has not entered the category of ‘righteous’, (meaning one who has mastered his emotions as well as his thought, speech, and deed,) has what to improve in the realm of emotion, and therefore has not necessarily ‘erased’ his past. Of course we have the responsibility to rectify our emotions, especially in the context of incidents that occurred due to our misuse of free choice, not just as a result of our inherent natures – which in any case must also be worked on.
Erasing negative impressions means that they must be ‘burned’ and ‘wiped out’. How do we do ‘burn’? Through fire. What is ‘holy fire’? Chassidut explains that the holy fire within a person, is when he arouses within himself a strong and forceful desire which says: “I want to be connected to HaShem! I am not willing to become disconnected, and be exposed or connected to all those negative scenes and impressions which are a part of the most external aspect of the world, and belong to the ‘husks’ (shells) of impurity. They are false imaginations, for they do not represent true existence, which is closeness and cleaving to G d, and fulfilling His will in the world.
As long as a person tells himself these things, in one manner or another, he arouses within himself a holy fire, and this holy fire burns and wipes out the evil images from his heart.
Another point from Tanya (the basic text of Chassidic thought by Rabbi Shneur Zalman of Liadi) that is important to emphasize, and which is also expressed in many letters from the Lubavitcher Rebbe, is that when a negative thought comes into a person’s mind, it is not necessary at all to address the thought, dwell on it, or relate to it, because someone who wrestles with an unsavoury character becomes affected by that person’s attributes, by virtue of his occupying himself with him. Even if the aim is to negate the thought, dwelling on it can make it more ‘real’ in one’s mind. So, as soon as a negative thought enters one’s mind, he must divert his attention from it as completely as possible, and divert his mind to a different topic, a topic which interests him and is close to his heart, and all the better if it’s in an area of holiness.
The concept mentioned above of arousing an internal will, forceful internal fire of the soul that wants to connect with HaShem, is a task incumbent on us in general, but not a direct remedy against the negative thoughts that affect us.
Aside from that, of course, the more a person is occupied with matters of Torah and Chassidut, Rebbe, holiness, its affects one in a peripheral way until it eventually lifts a person from the negative state he was in.
The Sages (of the Talmud) have promised us – “He who wishes to become purified, becomes helped (from above).” And certainly the Holy One Blessed be He sees the sincere will and positive desire of the person’s G dly soul, and aids him.
Another little tip, it is important to be involved with good deeds, the more the merrier! Also – to be always increasing in the performance of matters pertaining to holiness, this also causes detachment from negative matters. Sometimes even thoughts about how to fix the evil, come from the evil inclination that wishes us to be occupied with it, and ‘hopefully’ be sad on account of it. So it is preferable not to give in to its strategy, rather to serve G d with happiness and joy, with a positive look to the future. Best wishes!