The Yetser Hatov corresponds to the good or positive impulse in man, the Yetser Hara’ is his bad or negative impulse.

The good deeds of man have an effect on the four higher worlds, his bad deeds; on the four lower worlds. It is only when man sins, that the negative side can grow in strength. The negative aspect grows inside him; this is his Yetser Hara’, it cuts him off from the higher worlds, and uproots him from the Kedushah .

The Yetser Hara’ almost constantly tries to seduce him, and make him stumble, while the Yetser Hatov, on the other side, tries to attract him to Torah and Mitsvot and to help him do the Tikun (rectification) of his Neshama .

The two aspects of Yetser Tov and Yetser Hara’ were created to allow man to choose good over bad by his own free choice.

To ascend from its original level, a soul needs to reincarnate to do its Tikun. This Tikun of the soul is realized by the Gilgul (reincarnation) and/or by the ‘Ibur (attachment). While Gilgul is the reincarnation of a soul into a body from the time of its birth until its death, the ‘Ibur is an attachment of another soul to his own soul, that could come and leave at anytime.

If man does not do the Tikun for the level of his soul for which he came, he comes back and reincarnates in a new body for a new life. As long as he undertakes the Tikun of his soul in three reincarnations, he will come back again and again as needed, to complete his Tikun. However, if he maintains his wrong behavior and neither performs nor advances in his Tikun, he will not return after the third reincarnation.

There are different reasons why a soul might have to come back and reincarnate. It could be to repair or rectify an act for some damage he caused by his wrongdoings, or by not accomplishing the Mitsvot – commandments. The secret and reasons behind the accomplishment of the Mitsvot is to help, or make the Tikun of the soul.

As there are 613 parts to the soul, and 613 veins and bones to man, similarly, there are 613 Mitsvot and 613 lights in each Sephira or configuration. Each Mitsva corresponds to one part of the soul and of the body; by performing a positive commandment or avoiding a negative one, the corresponding part of the soul is reinforced and repaired. Failing to perform the positive Mitsva or to avoid a negative commandment causes direct damage to one’s soul and requires repair in this life or in a future reincarnation.

It is only by getting another chance to do or undo what he should have done or not do, that man makes the necessary Tikun of his soul, which can now rise to the higher realms and rejoin its source.

In Hebrew, the word “Tikun” has different meanings. It can be understood as reparation or rectification, and also as function, relation or action.

There are different types of Tikunim:
– Tikunim that took place in the first emanations to repair the worlds.
– Tikunim for the construction and inter-relations of the Sephirot and Partsufim (configurations).
– Tikunim of certain Partsufim (function or action) for the guidance of the worlds.
– Tikunim (rectifications) for the souls.
For more on Tikun, see Tikun under Kabbalah studies

Since the intention of the Creator is to bestow goodness on His creatures, all the levels of creation were put in place so His kindness could emanate to them, yet in such a way that they would be able to receive it. Complete rigor will be the destruction of anything not perfect, while complete kindness will permit everything without restriction. However, these two aspects are necessary to make the guidance of kindness and justice and to give man the possibility of serving the Creator by their free will.

After the Shvirat HaKelim (breaking of the vessels) with the emanation of the lights of the name MaH (45) and BaN (52), G-od could have done the Tikun (repair) of all the worlds, but then, there would not have been a reason for the participation of man in this Tikun and a possibility to acquire merit.

For man to have a possibility to act and repair the creation, G-od restrained in a way, his outflow of kindness to this world, to give men the merit of doing the Tikun with their free will. It is by their free will to get closer to their Creator and learn His ways, that men merit their place in the higher worlds when they depart.